refactor: rename internal Fai* design system + fai_ helpers to chain

The Studio design system, widgets and helpers carried a Fai* / fai_
prefix (FaiSpace, FaiColors, FaiTheme, FaiLog, 17 fai_*.dart files, the
faiBinary* l10n keys). Studio is the Ch∆In product, so rename them to
Chain* / chain_ — carefully preserving English fail/failure/failed.
Also fix stale references: the 'fai' binary in l10n strings -> 'chain',
FAI_* env vars (FAI_BIN/DATA_DIR/MODULES_DIR/TODAY/BOOTSTRAP_TOKEN) ->
CHAIN_*, fai_platform -> fai_chain, fai_hub -> chain_hub. Vendor
security-hook tooling (FAI_BANNED_TERMS_FILE) + the .fai bundle ext left.
flutter analyze + test: clean (20 passed).

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/widgets/chain_binary_recovery.dart

@@ -1,6 +1,6 @@
 // Recovery affordance shown when Studio cannot locate the `fai`
 // binary on the machine. Replaces the old CLI-jargon dead-end
-// ("set FAI_BIN to its full path") with two acts a non-CLI
+// ("set CHAIN_BIN to its full path") with two acts a non-CLI
 // operator can actually take:
 //
 //   1. Locate the binary with a native file picker, persisting
@@ -14,26 +14,26 @@ import '../data/system_actions.dart';
 import '../l10n/app_localizations.dart';
 import '../theme/tokens.dart';
 
-class FaiBinaryRecovery extends StatelessWidget {
+class ChainBinaryRecovery extends StatelessWidget {
   /// Fired after the operator successfully picks a `fai` binary,
   /// so the host can retry whatever action hit the missing
   /// binary (e.g. re-run the daemon start / status probe).
   final VoidCallback? onLocated;
 
-  const FaiBinaryRecovery({super.key, this.onLocated});
+  const ChainBinaryRecovery({super.key, this.onLocated});
 
   Future<void> _locate(BuildContext context) async {
     final l = AppLocalizations.of(context)!;
     final messenger = ScaffoldMessenger.of(context);
     final picked = await FilePicker.pickFiles(
-      dialogTitle: l.faiBinaryPickerTitle,
+      dialogTitle: l.chainBinaryPickerTitle,
     );
     final path = picked?.files.single.path;
     if (path == null) return;
     final ok = await SystemActions.setFaiBinaryPath(path);
     messenger.showSnackBar(
       SnackBar(
-        content: Text(ok ? l.faiBinarySetOk(path) : l.faiBinaryNotFound),
+        content: Text(ok ? l.chainBinarySetOk(path) : l.chainBinaryNotFound),
       ),
     );
     if (ok) onLocated?.call();
@@ -45,10 +45,10 @@ class FaiBinaryRecovery extends StatelessWidget {
     final l = AppLocalizations.of(context)!;
     return Container(
       width: double.infinity,
-      padding: const EdgeInsets.all(FaiSpace.md),
+      padding: const EdgeInsets.all(ChainSpace.md),
       decoration: BoxDecoration(
         color: theme.colorScheme.errorContainer.withValues(alpha: 0.4),
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         border: Border.all(
           color: theme.colorScheme.error.withValues(alpha: 0.4),
         ),
@@ -57,34 +57,34 @@ class FaiBinaryRecovery extends StatelessWidget {
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
           Text(
-            l.faiBinaryNotFound,
+            l.chainBinaryNotFound,
             style: theme.textTheme.bodyMedium?.copyWith(
               fontWeight: FontWeight.w600,
               color: theme.colorScheme.error,
             ),
           ),
-          const SizedBox(height: FaiSpace.xs),
+          const SizedBox(height: ChainSpace.xs),
           Text(
-            l.faiBinaryNotFoundHint,
+            l.chainBinaryNotFoundHint,
             style: theme.textTheme.bodySmall?.copyWith(
               color: theme.colorScheme.onSurfaceVariant,
             ),
           ),
-          const SizedBox(height: FaiSpace.md),
+          const SizedBox(height: ChainSpace.md),
           Wrap(
-            spacing: FaiSpace.sm,
-            runSpacing: FaiSpace.sm,
+            spacing: ChainSpace.sm,
+            runSpacing: ChainSpace.sm,
             children: [
               FilledButton.tonalIcon(
                 onPressed: () => _locate(context),
                 icon: const Icon(Icons.folder_open, size: 16),
-                label: Text(l.faiBinaryLocateButton),
+                label: Text(l.chainBinaryLocateButton),
               ),
               OutlinedButton.icon(
                 onPressed: () =>
                     SystemActions.openInOs(kFaiInstallDocsUrl),
                 icon: const Icon(Icons.open_in_new, size: 16),
-                label: Text(l.faiBinaryInstallDocsButton),
+                label: Text(l.chainBinaryInstallDocsButton),
               ),
             ],
           ),

lib/widgets/chain_card.dart

@@ -1,11 +1,11 @@
-// FaiCard — flat card with subtle accent gradient on the top
+// ChainCard — flat card with subtle accent gradient on the top
 // border. Replaces Material's default Card for the Ch∆In look.
 
 import 'package:flutter/material.dart';
 
 import '../theme/tokens.dart';
 
-class FaiCard extends StatelessWidget {
+class ChainCard extends StatelessWidget {
   /// Card body. Padding is applied internally; pass plain content.
   final Widget child;
 
@@ -18,15 +18,15 @@ class FaiCard extends StatelessWidget {
   /// Used by status rows (live event, healthy service).
   final Color? accentLeft;
 
-  /// Internal padding. Defaults to [FaiSpace.lg].
+  /// Internal padding. Defaults to [ChainSpace.lg].
   final EdgeInsetsGeometry padding;
 
-  const FaiCard({
+  const ChainCard({
     super.key,
     required this.child,
     this.accentTop = false,
     this.accentLeft,
-    this.padding = const EdgeInsets.all(FaiSpace.lg),
+    this.padding = const EdgeInsets.all(ChainSpace.lg),
   });
 
   @override
@@ -35,7 +35,7 @@ class FaiCard extends StatelessWidget {
     return Container(
       decoration: BoxDecoration(
         color: theme.colorScheme.surfaceContainer,
-        borderRadius: BorderRadius.circular(FaiRadius.md),
+        borderRadius: BorderRadius.circular(ChainRadius.md),
         border: Border.all(color: theme.colorScheme.outlineVariant),
       ),
       clipBehavior: Clip.antiAlias,
@@ -61,8 +61,8 @@ class FaiCard extends StatelessWidget {
             ),
           if (accentLeft != null)
             Positioned(
-              top: FaiSpace.md,
-              bottom: FaiSpace.md,
+              top: ChainSpace.md,
+              bottom: ChainSpace.md,
               left: 0,
               width: 3,
               child: DecoratedBox(

lib/widgets/chain_data_row.dart

@@ -1,4 +1,4 @@
-// FaiDataRow — Linear-style dense list row used by the audit
+// ChainDataRow — Linear-style dense list row used by the audit
 // stream. Hover-elevation, accent-coloured leading stripe, mono
 // timestamp, expressive type badge.
 
@@ -7,7 +7,7 @@ import 'package:flutter/material.dart';
 import '../theme/theme.dart';
 import '../theme/tokens.dart';
 
-class FaiDataRow extends StatefulWidget {
+class ChainDataRow extends StatefulWidget {
   /// Coloured leading stripe (4px). Used to encode event type
   /// (success / warning / failure) at a glance.
   final Color accent;
@@ -27,7 +27,7 @@ class FaiDataRow extends StatefulWidget {
   /// Optional tap handler.
   final VoidCallback? onTap;
 
-  const FaiDataRow({
+  const ChainDataRow({
     super.key,
     required this.accent,
     required this.leading,
@@ -38,10 +38,10 @@ class FaiDataRow extends StatefulWidget {
   });
 
   @override
-  State<FaiDataRow> createState() => _FaiDataRowState();
+  State<ChainDataRow> createState() => _FaiDataRowState();
 }
 
-class _FaiDataRowState extends State<FaiDataRow> {
+class _FaiDataRowState extends State<ChainDataRow> {
   bool _hovered = false;
 
   @override
@@ -57,12 +57,12 @@ class _FaiDataRowState extends State<FaiDataRow> {
         onTap: widget.onTap,
         behavior: HitTestBehavior.opaque,
         child: AnimatedContainer(
-          duration: FaiMotion.fast,
+          duration: ChainMotion.fast,
           decoration: BoxDecoration(
             color: _hovered
                 ? theme.colorScheme.surfaceContainerHigh
                 : theme.colorScheme.surfaceContainer,
-            borderRadius: BorderRadius.circular(FaiRadius.sm),
+            borderRadius: BorderRadius.circular(ChainRadius.sm),
             border: Border.all(
               color: _hovered
                   ? theme.colorScheme.outline
@@ -70,8 +70,8 @@ class _FaiDataRowState extends State<FaiDataRow> {
             ),
           ),
           padding: const EdgeInsets.symmetric(
-            horizontal: FaiSpace.md,
-            vertical: FaiSpace.sm,
+            horizontal: ChainSpace.md,
+            vertical: ChainSpace.sm,
           ),
           child: Row(
             children: [
@@ -83,12 +83,12 @@ class _FaiDataRowState extends State<FaiDataRow> {
                   borderRadius: BorderRadius.circular(2),
                 ),
               ),
-              const SizedBox(width: FaiSpace.md),
+              const SizedBox(width: ChainSpace.md),
               SizedBox(
                 width: 88,
                 child: Text(
                   widget.leading,
-                  style: FaiTheme.mono(
+                  style: ChainTheme.mono(
                     size: 11,
                     color: theme.colorScheme.onSurfaceVariant,
                   ),
@@ -98,7 +98,7 @@ class _FaiDataRowState extends State<FaiDataRow> {
                 width: 200,
                 child: Text(
                   widget.title,
-                  style: FaiTheme.mono(
+                  style: ChainTheme.mono(
                     size: 12,
                     weight: FontWeight.w500,
                     color: theme.colorScheme.onSurface,
@@ -116,10 +116,10 @@ class _FaiDataRowState extends State<FaiDataRow> {
               ),
               if (widget.trailing != null)
                 Padding(
-                  padding: const EdgeInsets.only(left: FaiSpace.md),
+                  padding: const EdgeInsets.only(left: ChainSpace.md),
                   child: Text(
                     widget.trailing!,
-                    style: FaiTheme.mono(
+                    style: ChainTheme.mono(
                       size: 11,
                       color: theme.colorScheme.onSurfaceVariant,
                     ),

lib/widgets/chain_delta_mark.dart

@@ -1,4 +1,4 @@
-// FaiDeltaMark — the Ch∆In signature element. A precise triangle
+// ChainDeltaMark — the Ch∆In signature element. A precise triangle
 // (∆) drawn from primitives, not a font glyph. Three states:
 //
 // - idle: static, accent colour, soft glow
@@ -12,25 +12,25 @@ import 'dart:math';
 
 import 'package:flutter/material.dart';
 
-enum FaiDeltaMode { idle, live, busy }
+enum ChainDeltaMode { idle, live, busy }
 
-class FaiDeltaMark extends StatefulWidget {
-  final FaiDeltaMode mode;
+class ChainDeltaMark extends StatefulWidget {
+  final ChainDeltaMode mode;
   final double size;
   final Color color;
 
-  const FaiDeltaMark({
+  const ChainDeltaMark({
     super.key,
     required this.color,
-    this.mode = FaiDeltaMode.idle,
+    this.mode = ChainDeltaMode.idle,
     this.size = 36,
   });
 
   @override
-  State<FaiDeltaMark> createState() => _FaiDeltaMarkState();
+  State<ChainDeltaMark> createState() => _FaiDeltaMarkState();
 }
 
-class _FaiDeltaMarkState extends State<FaiDeltaMark>
+class _FaiDeltaMarkState extends State<ChainDeltaMark>
     with SingleTickerProviderStateMixin {
   late final AnimationController _ctrl;
 
@@ -44,13 +44,13 @@ class _FaiDeltaMarkState extends State<FaiDeltaMark>
     _restart();
   }
 
-  Duration _durationFor(FaiDeltaMode m) {
+  Duration _durationFor(ChainDeltaMode m) {
     switch (m) {
-      case FaiDeltaMode.idle:
+      case ChainDeltaMode.idle:
         return const Duration(seconds: 1);
-      case FaiDeltaMode.live:
+      case ChainDeltaMode.live:
         return const Duration(milliseconds: 1600);
-      case FaiDeltaMode.busy:
+      case ChainDeltaMode.busy:
         return const Duration(seconds: 4);
     }
   }
@@ -58,21 +58,21 @@ class _FaiDeltaMarkState extends State<FaiDeltaMark>
   void _restart() {
     _ctrl.duration = _durationFor(widget.mode);
     switch (widget.mode) {
-      case FaiDeltaMode.idle:
+      case ChainDeltaMode.idle:
         _ctrl.stop();
         _ctrl.value = 0;
         break;
-      case FaiDeltaMode.live:
+      case ChainDeltaMode.live:
         _ctrl.repeat(reverse: true);
         break;
-      case FaiDeltaMode.busy:
+      case ChainDeltaMode.busy:
         _ctrl.repeat();
         break;
     }
   }
 
   @override
-  void didUpdateWidget(covariant FaiDeltaMark old) {
+  void didUpdateWidget(covariant ChainDeltaMark old) {
     super.didUpdateWidget(old);
     if (old.mode != widget.mode) _restart();
   }
@@ -103,7 +103,7 @@ class _FaiDeltaMarkState extends State<FaiDeltaMark>
 
 class _DeltaPainter extends CustomPainter {
   final Color color;
-  final FaiDeltaMode mode;
+  final ChainDeltaMode mode;
   final double t;
 
   _DeltaPainter({required this.color, required this.mode, required this.t});
@@ -115,12 +115,12 @@ class _DeltaPainter extends CustomPainter {
 
     // In live mode: scale the whole mark between 0.85 and 1.15
     // so the pulse is visible without staring. Idle stays at 1.0.
-    final scale = mode == FaiDeltaMode.live ? 0.85 + 0.30 * t : 1.0;
+    final scale = mode == ChainDeltaMode.live ? 0.85 + 0.30 * t : 1.0;
     final r = size.width * 0.36 * scale;
 
     canvas.save();
     canvas.translate(cx, cy);
-    if (mode == FaiDeltaMode.busy) {
+    if (mode == ChainDeltaMode.busy) {
       canvas.rotate(t * 2 * pi);
     }
 
@@ -133,8 +133,8 @@ class _DeltaPainter extends CustomPainter {
 
     // Glow halo. In live mode the glow ring grows with the pulse
     // and the alpha breathes harder.
-    if (mode != FaiDeltaMode.idle) {
-      final pulseStrength = mode == FaiDeltaMode.live ? t : 1.0;
+    if (mode != ChainDeltaMode.idle) {
+      final pulseStrength = mode == ChainDeltaMode.live ? t : 1.0;
       final glow = Paint()
         ..color = color.withValues(alpha: 0.30 + 0.40 * pulseStrength)
         ..maskFilter = MaskFilter.blur(BlurStyle.normal, 8 + 14 * pulseStrength)
@@ -143,7 +143,7 @@ class _DeltaPainter extends CustomPainter {
     }
 
     // Filled triangle, brighter on the up-beat for live mode.
-    final fillAlpha = mode == FaiDeltaMode.live ? 0.15 + 0.20 * t : 0.18;
+    final fillAlpha = mode == ChainDeltaMode.live ? 0.15 + 0.20 * t : 0.18;
     final fill = Paint()
       ..color = color.withValues(alpha: fillAlpha)
       ..style = PaintingStyle.fill;
@@ -158,7 +158,7 @@ class _DeltaPainter extends CustomPainter {
     canvas.drawPath(path, stroke);
 
     // Inner accent dot.
-    final dotAlpha = mode == FaiDeltaMode.live ? 0.55 + 0.45 * t : 1.0;
+    final dotAlpha = mode == ChainDeltaMode.live ? 0.55 + 0.45 * t : 1.0;
     final dot = Paint()
       ..color = color.withValues(alpha: dotAlpha)
       ..style = PaintingStyle.fill;

lib/widgets/chain_empty_state.dart

@@ -1,4 +1,4 @@
-// FaiEmptyState — gracious empty / loading / error placeholder.
+// ChainEmptyState — gracious empty / loading / error placeholder.
 // Replaces "(no data)" strings with one tone, one icon, one tip.
 //
 // The blank surface is where an app most easily feels unfinished,
@@ -11,9 +11,9 @@
 import 'package:flutter/material.dart';
 
 import '../theme/tokens.dart';
-import 'fai_delta_mark.dart';
+import 'chain_delta_mark.dart';
 
-class FaiEmptyState extends StatelessWidget {
+class ChainEmptyState extends StatelessWidget {
   final IconData icon;
   final String title;
   final String? hint;
@@ -23,7 +23,7 @@ class FaiEmptyState extends StatelessWidget {
   /// for connection-failure variants.
   final Color? iconColor;
 
-  const FaiEmptyState({
+  const ChainEmptyState({
     super.key,
     required this.icon,
     required this.title,
@@ -40,7 +40,7 @@ class FaiEmptyState extends StatelessWidget {
       child: ConstrainedBox(
         constraints: const BoxConstraints(maxWidth: 440),
         child: Padding(
-          padding: const EdgeInsets.all(FaiSpace.xxl),
+          padding: const EdgeInsets.all(ChainSpace.xxl),
           child: Column(
             mainAxisAlignment: MainAxisAlignment.center,
             mainAxisSize: MainAxisSize.min,
@@ -57,7 +57,7 @@ class FaiEmptyState extends StatelessWidget {
                   children: [
                     Opacity(
                       opacity: 0.10,
-                      child: FaiDeltaMark(
+                      child: ChainDeltaMark(
                         color: theme.colorScheme.primary,
                         size: 112,
                       ),
@@ -71,14 +71,14 @@ class FaiEmptyState extends StatelessWidget {
                         border: Border.all(
                           color: color.withValues(alpha: 0.18),
                         ),
-                        boxShadow: FaiElevation.low(theme.brightness),
+                        boxShadow: ChainElevation.low(theme.brightness),
                       ),
                       child: Icon(icon, size: 26, color: color),
                     ),
                   ],
                 ),
               ),
-              const SizedBox(height: FaiSpace.xl),
+              const SizedBox(height: ChainSpace.xl),
               Text(
                 title,
                 textAlign: TextAlign.center,
@@ -87,7 +87,7 @@ class FaiEmptyState extends StatelessWidget {
                 ),
               ),
               if (hint != null) ...[
-                const SizedBox(height: FaiSpace.sm),
+                const SizedBox(height: ChainSpace.sm),
                 Text(
                   hint!,
                   textAlign: TextAlign.center,
@@ -98,7 +98,7 @@ class FaiEmptyState extends StatelessWidget {
                 ),
               ],
               if (action != null) ...[
-                const SizedBox(height: FaiSpace.xl),
+                const SizedBox(height: ChainSpace.xl),
                 action!,
               ],
             ],

lib/widgets/chain_en_badge.dart

@@ -1,4 +1,4 @@
-// FaiEnBadge — small "[EN]" pill shown next to text that came
+// ChainEnBadge — small "[EN]" pill shown next to text that came
 // from outside Studio's localization pipeline (MCP server tool
 // names, n8n endpoint descriptions, native LLM responses).
 //
@@ -14,21 +14,21 @@ import 'package:flutter/material.dart';
 import '../l10n/app_localizations.dart';
 import '../theme/tokens.dart';
 
-class FaiEnBadge extends StatelessWidget {
+class ChainEnBadge extends StatelessWidget {
   /// When true, the badge renders. When false (e.g. the active
   /// locale already is English), it returns
   /// `SizedBox.shrink()` so callers can drop it inline without
   /// guarding visibility themselves.
   final bool visible;
 
-  const FaiEnBadge({super.key, required this.visible});
+  const ChainEnBadge({super.key, required this.visible});
 
   /// Convenience constructor: derives `visible` from the active
   /// Localizations locale. Use this from inside a Build method
   /// where you already have a BuildContext.
-  factory FaiEnBadge.forContext(BuildContext context) {
+  factory ChainEnBadge.forContext(BuildContext context) {
     final lang = Localizations.localeOf(context).languageCode;
-    return FaiEnBadge(visible: lang != 'en');
+    return ChainEnBadge(visible: lang != 'en');
   }
 
   @override
@@ -42,7 +42,7 @@ class FaiEnBadge extends StatelessWidget {
         padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 1),
         decoration: BoxDecoration(
           color: theme.colorScheme.surfaceContainerHighest,
-          borderRadius: BorderRadius.circular(FaiRadius.sm),
+          borderRadius: BorderRadius.circular(ChainRadius.sm),
           border: Border.all(color: theme.colorScheme.outlineVariant),
         ),
         child: Text(

lib/widgets/chain_error_box.dart

@@ -1,4 +1,4 @@
-// FaiErrorBox — selectable monospace error / output block with
+// ChainErrorBox — selectable monospace error / output block with
 // a small copy-to-clipboard button in the top-right corner.
 //
 // Used wherever the operator might want to paste daemon stderr
@@ -15,7 +15,7 @@ import '../l10n/app_localizations.dart';
 import '../theme/theme.dart';
 import '../theme/tokens.dart';
 
-class FaiErrorBox extends StatefulWidget {
+class ChainErrorBox extends StatefulWidget {
   /// The text the operator wants to read (and copy). Rendered
   /// monospace, selectable, multi-line. Ignored when [error] is
   /// supplied.
@@ -41,7 +41,7 @@ class FaiErrorBox extends StatefulWidget {
   /// trailers otherwise.
   final Object? error;
 
-  const FaiErrorBox({
+  const ChainErrorBox({
     super.key,
     this.text = '',
     this.isError = false,
@@ -49,14 +49,14 @@ class FaiErrorBox extends StatefulWidget {
     this.error,
   }) : assert(
          text != '' || error != null,
-         'FaiErrorBox needs either text or error',
+         'ChainErrorBox needs either text or error',
        );
 
   @override
-  State<FaiErrorBox> createState() => _FaiErrorBoxState();
+  State<ChainErrorBox> createState() => _FaiErrorBoxState();
 }
 
-class _FaiErrorBoxState extends State<FaiErrorBox> {
+class _FaiErrorBoxState extends State<ChainErrorBox> {
   bool _justCopied = false;
   bool _detailExpanded = false;
 
@@ -86,14 +86,14 @@ class _FaiErrorBoxState extends State<FaiErrorBox> {
     return Container(
       width: double.infinity,
       padding: const EdgeInsets.fromLTRB(
-        FaiSpace.sm,
-        FaiSpace.xs,
-        FaiSpace.xs,
-        FaiSpace.sm,
+        ChainSpace.sm,
+        ChainSpace.xs,
+        ChainSpace.xs,
+        ChainSpace.sm,
       ),
       decoration: BoxDecoration(
         color: theme.colorScheme.surfaceContainerHigh,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         border: Border.all(color: accent.withValues(alpha: 0.4)),
       ),
       child: Column(
@@ -133,7 +133,7 @@ class _FaiErrorBoxState extends State<FaiErrorBox> {
               ),
             ],
             if (friendly.detail.isNotEmpty) ...[
-              const SizedBox(height: FaiSpace.sm),
+              const SizedBox(height: ChainSpace.sm),
               InkWell(
                 onTap: () => setState(() {
                   _detailExpanded = !_detailExpanded;
@@ -159,7 +159,7 @@ class _FaiErrorBoxState extends State<FaiErrorBox> {
                 ),
               ),
               if (_detailExpanded) ...[
-                const SizedBox(height: FaiSpace.xs),
+                const SizedBox(height: ChainSpace.xs),
                 ConstrainedBox(
                   constraints: BoxConstraints(
                     maxHeight: widget.maxHeight ?? double.infinity,
@@ -168,7 +168,7 @@ class _FaiErrorBoxState extends State<FaiErrorBox> {
                     child: SingleChildScrollView(
                       child: SelectableText(
                         friendly.detail,
-                        style: FaiTheme.mono(
+                        style: ChainTheme.mono(
                           size: 11,
                           color: theme.colorScheme.onSurfaceVariant,
                         ),
@@ -187,7 +187,7 @@ class _FaiErrorBoxState extends State<FaiErrorBox> {
                 child: SingleChildScrollView(
                   child: SelectableText(
                     widget.text,
-                    style: FaiTheme.mono(size: 11, color: fg),
+                    style: ChainTheme.mono(size: 11, color: fg),
                   ),
                 ),
               ),

lib/widgets/chain_flow_output.dart

@@ -1,4 +1,4 @@
-// FaiFlowOutput — type-aware renderer for one entry in
+// ChainFlowOutput — type-aware renderer for one entry in
 // `runSavedFlow`'s output map. Reads `FlowOutput` and dispatches
 // to the right widget:
 //
@@ -27,10 +27,10 @@ import '../l10n/app_localizations.dart';
 import '../theme/theme.dart';
 import '../theme/tokens.dart';
 
-class FaiFlowOutput extends StatelessWidget {
+class ChainFlowOutput extends StatelessWidget {
   final FlowOutput output;
 
-  const FaiFlowOutput({super.key, required this.output});
+  const ChainFlowOutput({super.key, required this.output});
 
   @override
   Widget build(BuildContext context) {
@@ -75,10 +75,10 @@ class _TextView extends StatelessWidget {
     if (_looksLikeMarkdown) {
       return Container(
         width: double.infinity,
-        padding: const EdgeInsets.all(FaiSpace.md),
+        padding: const EdgeInsets.all(ChainSpace.md),
         decoration: BoxDecoration(
           color: theme.colorScheme.surfaceContainerHigh,
-          borderRadius: BorderRadius.circular(FaiRadius.sm),
+          borderRadius: BorderRadius.circular(ChainRadius.sm),
           border: Border.all(color: theme.colorScheme.outlineVariant),
         ),
         child: MarkdownBody(
@@ -89,16 +89,16 @@ class _TextView extends StatelessWidget {
               await SystemActions.openInOs(href);
             }
           },
-          styleSheet: FaiTheme.markdownStyle(theme),
+          styleSheet: ChainTheme.markdownStyle(theme),
         ),
       );
     }
     return Container(
       width: double.infinity,
-      padding: const EdgeInsets.all(FaiSpace.md),
+      padding: const EdgeInsets.all(ChainSpace.md),
       decoration: BoxDecoration(
         color: theme.colorScheme.surfaceContainerHigh,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         border: Border.all(color: theme.colorScheme.outlineVariant),
       ),
       child: SelectableText(
@@ -119,15 +119,15 @@ class _CodeBlock extends StatelessWidget {
   Widget build(BuildContext context) {
     return Container(
       width: double.infinity,
-      padding: const EdgeInsets.all(FaiSpace.md),
+      padding: const EdgeInsets.all(ChainSpace.md),
       decoration: BoxDecoration(
         color: theme.colorScheme.surfaceContainerHigh,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         border: Border.all(color: theme.colorScheme.outlineVariant),
       ),
       child: SelectableText(
         text,
-        style: FaiTheme.mono(size: 12, color: theme.colorScheme.onSurface),
+        style: ChainTheme.mono(size: 12, color: theme.colorScheme.onSurface),
       ),
     );
   }
@@ -183,10 +183,10 @@ class _BytesView extends StatelessWidget {
     final l = AppLocalizations.of(context)!;
     return Container(
       width: double.infinity,
-      padding: const EdgeInsets.all(FaiSpace.md),
+      padding: const EdgeInsets.all(ChainSpace.md),
       decoration: BoxDecoration(
         color: theme.colorScheme.surfaceContainerHigh,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         border: Border.all(color: theme.colorScheme.outlineVariant),
       ),
       child: Column(
@@ -196,11 +196,11 @@ class _BytesView extends StatelessWidget {
             ConstrainedBox(
               constraints: const BoxConstraints(maxHeight: 240),
               child: ClipRRect(
-                borderRadius: BorderRadius.circular(FaiRadius.sm),
+                borderRadius: BorderRadius.circular(ChainRadius.sm),
                 child: Image.memory(bytes, fit: BoxFit.contain),
               ),
             ),
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
           ],
           Text(
             '${mimeType.isEmpty ? l.flowsOutputBytesUnknownMime : mimeType}'
@@ -209,7 +209,7 @@ class _BytesView extends StatelessWidget {
               color: theme.colorScheme.onSurfaceVariant,
             ),
           ),
-          const SizedBox(height: FaiSpace.sm),
+          const SizedBox(height: ChainSpace.sm),
           OutlinedButton.icon(
             icon: const Icon(Icons.save_alt, size: 16),
             label: Text(l.flowsOutputSaveAs),
@@ -247,10 +247,10 @@ class _FileView extends StatelessWidget {
     final l = AppLocalizations.of(context)!;
     return Container(
       width: double.infinity,
-      padding: const EdgeInsets.all(FaiSpace.md),
+      padding: const EdgeInsets.all(ChainSpace.md),
       decoration: BoxDecoration(
         color: theme.colorScheme.surfaceContainerHigh,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         border: Border.all(color: theme.colorScheme.outlineVariant),
       ),
       child: Column(
@@ -258,7 +258,7 @@ class _FileView extends StatelessWidget {
         children: [
           SelectableText(
             uri,
-            style: FaiTheme.mono(size: 11, color: theme.colorScheme.primary),
+            style: ChainTheme.mono(size: 11, color: theme.colorScheme.primary),
           ),
           if (mimeType.isNotEmpty) ...[
             const SizedBox(height: 4),
@@ -269,7 +269,7 @@ class _FileView extends StatelessWidget {
               ),
             ),
           ],
-          const SizedBox(height: FaiSpace.sm),
+          const SizedBox(height: ChainSpace.sm),
           OutlinedButton.icon(
             icon: const Icon(Icons.open_in_new, size: 16),
             label: Text(l.flowsOutputOpen),

lib/widgets/chain_log_viewer.dart

@@ -1,4 +1,4 @@
-// FaiLogViewer — modal sheet that renders a log file inline with
+// ChainLogViewer — modal sheet that renders a log file inline with
 // line numbers, basic syntax colouring and a Copy-all button.
 //
 // Use [showFaiLogViewer] to open it. Two log shapes are supported
@@ -9,7 +9,7 @@
 //     anything else renders neutral.
 //   - tracing text (the daemon's `~/.chain/run/<channel>.log`):
 //     `[INFO]`, `[WARN]`, `[ERROR]`, `[DEBUG]` substrings get the
-//     matching tone from the FaiTheme palette.
+//     matching tone from the ChainTheme palette.
 //
 // The viewer reads the *last* N lines (default 500) to keep
 // rendering snappy on huge log files. A Refresh button re-reads
@@ -42,7 +42,7 @@ Future<void> showFaiLogViewer(
   return showDialog<void>(
     context: context,
     barrierDismissible: true,
-    builder: (_) => FaiLogViewer(
+    builder: (_) => ChainLogViewer(
       path: path,
       title: title ?? path.split(Platform.pathSeparator).last,
       tailLines: tailLines,
@@ -72,7 +72,7 @@ Future<void> showFaiConfigViewer(
   );
 }
 
-class FaiLogViewer extends StatefulWidget {
+class ChainLogViewer extends StatefulWidget {
   final String path;
   final String title;
   final int tailLines;
@@ -84,7 +84,7 @@ class FaiLogViewer extends StatefulWidget {
   /// (for config / plain-text files).
   final bool plain;
 
-  const FaiLogViewer({
+  const ChainLogViewer({
     super.key,
     required this.path,
     required this.title,
@@ -94,10 +94,10 @@ class FaiLogViewer extends StatefulWidget {
   });
 
   @override
-  State<FaiLogViewer> createState() => _FaiLogViewerState();
+  State<ChainLogViewer> createState() => _FaiLogViewerState();
 }
 
-class _FaiLogViewerState extends State<FaiLogViewer> {
+class _FaiLogViewerState extends State<ChainLogViewer> {
   List<String> _lines = const <String>[];
   bool _loading = true;
   bool _justCopied = false;
@@ -141,8 +141,8 @@ class _FaiLogViewerState extends State<FaiLogViewer> {
     final l = AppLocalizations.of(context)!;
     return Dialog(
       insetPadding: const EdgeInsets.symmetric(
-        horizontal: FaiSpace.xl,
-        vertical: FaiSpace.xl,
+        horizontal: ChainSpace.xl,
+        vertical: ChainSpace.xl,
       ),
       child: ConstrainedBox(
         constraints: const BoxConstraints(maxWidth: 980, maxHeight: 720),
@@ -169,7 +169,7 @@ class _FaiLogViewerState extends State<FaiLogViewer> {
                   : _lines.isEmpty
                   ? Center(
                       child: Padding(
-                        padding: const EdgeInsets.all(FaiSpace.xl),
+                        padding: const EdgeInsets.all(ChainSpace.xl),
                         child: Text(
                           l.logViewerEmpty,
                           style: theme.textTheme.bodySmall?.copyWith(
@@ -218,10 +218,10 @@ class _Header extends StatelessWidget {
     final l = AppLocalizations.of(context)!;
     return Padding(
       padding: const EdgeInsets.fromLTRB(
-        FaiSpace.lg,
-        FaiSpace.md,
-        FaiSpace.sm,
-        FaiSpace.md,
+        ChainSpace.lg,
+        ChainSpace.md,
+        ChainSpace.sm,
+        ChainSpace.md,
       ),
       child: Row(
         children: [
@@ -230,7 +230,7 @@ class _Header extends StatelessWidget {
             size: 18,
             color: theme.colorScheme.onSurfaceVariant,
           ),
-          const SizedBox(width: FaiSpace.sm),
+          const SizedBox(width: ChainSpace.sm),
           Expanded(
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
@@ -246,7 +246,7 @@ class _Header extends StatelessWidget {
                 const SizedBox(height: 2),
                 Text(
                   '$path · ${l.logViewerLineCount(lineCount)}',
-                  style: FaiTheme.mono(
+                  style: ChainTheme.mono(
                     size: 10,
                     color: theme.colorScheme.onSurfaceVariant,
                   ),
@@ -296,7 +296,7 @@ class _LogBody extends StatelessWidget {
     final gutterWidth = 12.0 + 8.0 * lines.length.toString().length;
     return Scrollbar(
       child: ListView.builder(
-        padding: const EdgeInsets.symmetric(vertical: FaiSpace.sm),
+        padding: const EdgeInsets.symmetric(vertical: ChainSpace.sm),
         itemCount: lines.length,
         itemBuilder: (context, i) => _LogLine(
           lineNumber: i + 1,
@@ -328,7 +328,7 @@ class _LogLine extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return Padding(
-      padding: const EdgeInsets.symmetric(horizontal: FaiSpace.sm, vertical: 1),
+      padding: const EdgeInsets.symmetric(horizontal: ChainSpace.sm, vertical: 1),
       child: Row(
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
@@ -337,7 +337,7 @@ class _LogLine extends StatelessWidget {
             child: Text(
               '$lineNumber',
               textAlign: TextAlign.right,
-              style: FaiTheme.mono(
+              style: ChainTheme.mono(
                 size: 11,
                 color: theme.colorScheme.onSurfaceVariant.withValues(
                   alpha: 0.6,
@@ -345,7 +345,7 @@ class _LogLine extends StatelessWidget {
               ),
             ),
           ),
-          const SizedBox(width: FaiSpace.sm),
+          const SizedBox(width: ChainSpace.sm),
           Expanded(
             child: SelectableText.rich(
               plain
@@ -354,7 +354,7 @@ class _LogLine extends StatelessWidget {
                       style: TextStyle(color: theme.colorScheme.onSurface),
                     )
                   : _highlightLine(text, theme),
-              style: FaiTheme.mono(
+              style: ChainTheme.mono(
                 size: 11,
                 color: theme.colorScheme.onSurface,
               ),
@@ -388,7 +388,7 @@ TextSpan _highlightJsonLine(String line, ThemeData theme) {
     color: theme.colorScheme.primary,
     fontWeight: FontWeight.w600,
   );
-  final stringStyle = TextStyle(color: FaiColors.success);
+  final stringStyle = TextStyle(color: ChainColors.success);
   final errorStringStyle = TextStyle(color: theme.colorScheme.error);
 
   final keyRe = RegExp(r'"(ts|level|source|error|context)"\s*:');
@@ -440,7 +440,7 @@ TextSpan _highlightTraceLine(String line, ThemeData theme) {
       break;
     case 'WARN':
     case 'WARNING':
-      tone = FaiColors.warning;
+      tone = ChainColors.warning;
       break;
     case 'INFO':
       tone = theme.colorScheme.primary;

lib/widgets/chain_module_sheet.dart

@@ -1,4 +1,4 @@
-// FaiModuleSheet — modal bottom-sheet showing detailed module
+// ChainModuleSheet — modal bottom-sheet showing detailed module
 // info: full capability list, declared permissions, on-disk
 // directory. Opened by tapping a module card on the Modules
 // page.
@@ -11,12 +11,12 @@ import '../l10n/app_localizations.dart';
 import '../pages/welcome.dart' show showFaiDoc;
 import '../theme/theme.dart';
 import '../theme/tokens.dart';
-import 'fai_pill.dart';
+import 'chain_pill.dart';
 
-class FaiModuleSheet extends StatefulWidget {
+class ChainModuleSheet extends StatefulWidget {
   final String moduleName;
 
-  const FaiModuleSheet({super.key, required this.moduleName});
+  const ChainModuleSheet({super.key, required this.moduleName});
 
   /// Convenience launcher used from the Modules list. Resolves
   /// to `true` when the operator uninstalled the module — the
@@ -28,18 +28,18 @@ class FaiModuleSheet extends StatefulWidget {
       isScrollControlled: true,
       elevation: 8,
       shape: const RoundedRectangleBorder(
-        borderRadius: BorderRadius.vertical(top: Radius.circular(FaiRadius.md)),
+        borderRadius: BorderRadius.vertical(top: Radius.circular(ChainRadius.md)),
       ),
-      builder: (_) => FaiModuleSheet(moduleName: name),
+      builder: (_) => ChainModuleSheet(moduleName: name),
     );
     return r ?? false;
   }
 
   @override
-  State<FaiModuleSheet> createState() => _FaiModuleSheetState();
+  State<ChainModuleSheet> createState() => _FaiModuleSheetState();
 }
 
-class _FaiModuleSheetState extends State<FaiModuleSheet> {
+class _FaiModuleSheetState extends State<ChainModuleSheet> {
   late final Future<ModuleDetail> _future;
   bool _uninstalling = false;
 
@@ -127,12 +127,12 @@ class _FaiModuleSheetState extends State<FaiModuleSheet> {
               _Handle(),
               if (snapshot.connectionState == ConnectionState.waiting)
                 const Padding(
-                  padding: EdgeInsets.all(FaiSpace.xxxl),
+                  padding: EdgeInsets.all(ChainSpace.xxxl),
                   child: CircularProgressIndicator(),
                 )
               else if (snapshot.hasError)
                 Padding(
-                  padding: const EdgeInsets.all(FaiSpace.xl),
+                  padding: const EdgeInsets.all(ChainSpace.xl),
                   child: Text(
                     AppLocalizations.of(
                       context,
@@ -163,7 +163,7 @@ class _Handle extends StatelessWidget {
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
     return Padding(
-      padding: const EdgeInsets.symmetric(vertical: FaiSpace.sm),
+      padding: const EdgeInsets.symmetric(vertical: ChainSpace.sm),
       child: Container(
         width: 40,
         height: 4,
@@ -193,10 +193,10 @@ class _Body extends StatelessWidget {
     final l = AppLocalizations.of(context)!;
     return ListView(
       padding: const EdgeInsets.fromLTRB(
-        FaiSpace.xxl,
-        FaiSpace.md,
-        FaiSpace.xxl,
-        FaiSpace.xxl,
+        ChainSpace.xxl,
+        ChainSpace.md,
+        ChainSpace.xxl,
+        ChainSpace.xxl,
       ),
       shrinkWrap: true,
       children: [
@@ -208,39 +208,39 @@ class _Body extends StatelessWidget {
                 fontWeight: FontWeight.w600,
               ),
             ),
-            const SizedBox(width: FaiSpace.md),
-            FaiPill(
+            const SizedBox(width: ChainSpace.md),
+            ChainPill(
               label: 'v${detail.version}',
-              tone: FaiPillTone.accent,
+              tone: ChainPillTone.accent,
               monospace: true,
             ),
           ],
         ),
-        const SizedBox(height: FaiSpace.xs),
+        const SizedBox(height: ChainSpace.xs),
         SelectableText(
           detail.directory,
-          style: FaiTheme.mono(
+          style: ChainTheme.mono(
             size: 11,
             color: theme.colorScheme.onSurfaceVariant,
           ),
         ),
-        const SizedBox(height: FaiSpace.xl),
+        const SizedBox(height: ChainSpace.xl),
         _SectionHeader(l.moduleSheetCapabilities),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         Wrap(
-          spacing: FaiSpace.xs,
-          runSpacing: FaiSpace.xs,
+          spacing: ChainSpace.xs,
+          runSpacing: ChainSpace.xs,
           children: detail.capabilities
               .map(
-                (c) => FaiPill(
+                (c) => ChainPill(
                   label: c,
-                  tone: FaiPillTone.accent,
+                  tone: ChainPillTone.accent,
                   monospace: true,
                 ),
               )
               .toList(),
         ),
-        const SizedBox(height: FaiSpace.xl),
+        const SizedBox(height: ChainSpace.xl),
         Row(
           children: [
             _SectionHeader(l.moduleSheetPermissions),
@@ -259,7 +259,7 @@ class _Body extends StatelessWidget {
             ),
           ],
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         if (detail.permissions.isEmpty)
           Text(
             l.moduleSheetNoPermissions,
@@ -282,10 +282,10 @@ class _Body extends StatelessWidget {
                           size: 14,
                           color: theme.colorScheme.onSurfaceVariant,
                         ),
-                        const SizedBox(width: FaiSpace.sm),
+                        const SizedBox(width: ChainSpace.sm),
                         SelectableText(
                           p,
-                          style: FaiTheme.mono(
+                          style: ChainTheme.mono(
                             size: 12,
                             color: theme.colorScheme.onSurface,
                           ),
@@ -296,7 +296,7 @@ class _Body extends StatelessWidget {
                 )
                 .toList(),
           ),
-        const SizedBox(height: FaiSpace.xxl),
+        const SizedBox(height: ChainSpace.xxl),
         Row(
           children: [
             const Spacer(),
@@ -378,7 +378,7 @@ class _UninstallVersionPickerDialogState
         mainAxisSize: MainAxisSize.min,
         children: [
           Text(l.uninstallVersionPickerBody(widget.moduleName)),
-          const SizedBox(height: FaiSpace.md),
+          const SizedBox(height: ChainSpace.md),
           RadioGroup<String>(
             groupValue: _picked,
             onChanged: (val) {

lib/widgets/chain_pill.dart

@@ -1,4 +1,4 @@
-// FaiPill — small inline label. Used for capabilities, versions,
+// ChainPill — small inline label. Used for capabilities, versions,
 // permission scopes, status text. Replaces ad-hoc Container chips.
 
 import 'package:flutter/material.dart';
@@ -6,18 +6,18 @@ import 'package:flutter/material.dart';
 import '../theme/theme.dart';
 import '../theme/tokens.dart';
 
-enum FaiPillTone { neutral, accent, success, warning, danger }
+enum ChainPillTone { neutral, accent, success, warning, danger }
 
-class FaiPill extends StatelessWidget {
+class ChainPill extends StatelessWidget {
   final String label;
-  final FaiPillTone tone;
+  final ChainPillTone tone;
   final IconData? icon;
   final bool monospace;
 
-  const FaiPill({
+  const ChainPill({
     super.key,
     required this.label,
-    this.tone = FaiPillTone.neutral,
+    this.tone = ChainPillTone.neutral,
     this.icon,
     this.monospace = false,
   });
@@ -27,13 +27,13 @@ class FaiPill extends StatelessWidget {
     final theme = Theme.of(context);
     final (bg, fg) = _colors(theme.colorScheme);
     final textStyle = monospace
-        ? FaiTheme.mono(size: 11, weight: FontWeight.w500, color: fg)
+        ? ChainTheme.mono(size: 11, weight: FontWeight.w500, color: fg)
         : theme.textTheme.labelSmall?.copyWith(color: fg);
     return Container(
-      padding: const EdgeInsets.symmetric(horizontal: FaiSpace.sm, vertical: 3),
+      padding: const EdgeInsets.symmetric(horizontal: ChainSpace.sm, vertical: 3),
       decoration: BoxDecoration(
         color: bg,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
       ),
       child: Row(
         mainAxisSize: MainAxisSize.min,
@@ -50,25 +50,25 @@ class FaiPill extends StatelessWidget {
 
   (Color, Color) _colors(ColorScheme scheme) {
     switch (tone) {
-      case FaiPillTone.neutral:
+      case ChainPillTone.neutral:
         return (scheme.surfaceContainerHighest, scheme.onSurfaceVariant);
-      case FaiPillTone.accent:
+      case ChainPillTone.accent:
         return (scheme.primary.withValues(alpha: 0.15), scheme.primary);
-      case FaiPillTone.success:
+      case ChainPillTone.success:
         return (
-          FaiColors.success.withValues(alpha: 0.15),
+          ChainColors.success.withValues(alpha: 0.15),
           scheme.brightness == Brightness.dark
-              ? FaiColors.success
+              ? ChainColors.success
               : const Color(0xFF15803D),
         );
-      case FaiPillTone.warning:
+      case ChainPillTone.warning:
         return (
-          FaiColors.warning.withValues(alpha: 0.15),
+          ChainColors.warning.withValues(alpha: 0.15),
           scheme.brightness == Brightness.dark
-              ? FaiColors.warning
+              ? ChainColors.warning
               : const Color(0xFFB45309),
         );
-      case FaiPillTone.danger:
+      case ChainPillTone.danger:
         return (scheme.errorContainer, scheme.onErrorContainer);
     }
   }

lib/widgets/chain_search_palette.dart

@@ -1,4 +1,4 @@
-// FaiSearchPalette — global Cmd+K command bar.
+// ChainSearchPalette — global Cmd+K command bar.
 //
 // Indexes: nav destinations, installed modules, store entries,
 // saved flows. Filters client-side as the operator types.
@@ -12,12 +12,12 @@ import 'package:flutter/services.dart';
 
 import '../data/hub.dart';
 import '../l10n/app_localizations.dart';
-import 'fai_module_sheet.dart';
+import 'chain_module_sheet.dart';
 
 /// One row in the palette. Carries everything needed to render
 /// + dispatch — keep it serializable-shaped so we can persist
 /// recent picks later.
-class FaiSearchHit {
+class ChainSearchHit {
   final String label;
   final String hint;
   final IconData icon;
@@ -33,7 +33,7 @@ class FaiSearchHit {
   /// Action to run when this hit is selected.
   final VoidCallback onSelect;
 
-  FaiSearchHit({
+  ChainSearchHit({
     required this.label,
     required this.hint,
     required this.icon,
@@ -42,33 +42,33 @@ class FaiSearchHit {
   }) : haystack = '$label $hint $group'.toLowerCase();
 }
 
-class FaiSearchPalette extends StatefulWidget {
+class ChainSearchPalette extends StatefulWidget {
   /// Pages the operator can navigate to. Each entry maps to a
   /// callback that selects the right tab back in the shell.
-  final List<FaiSearchHit> staticHits;
+  final List<ChainSearchHit> staticHits;
 
-  const FaiSearchPalette({super.key, required this.staticHits});
+  const ChainSearchPalette({super.key, required this.staticHits});
 
   /// Convenience launcher — used from the Cmd+K shortcut.
   static Future<void> show(
     BuildContext context, {
-    required List<FaiSearchHit> staticHits,
+    required List<ChainSearchHit> staticHits,
   }) {
     return showDialog<void>(
       context: context,
       barrierColor: Colors.black54,
-      builder: (_) => FaiSearchPalette(staticHits: staticHits),
+      builder: (_) => ChainSearchPalette(staticHits: staticHits),
     );
   }
 
   @override
-  State<FaiSearchPalette> createState() => _FaiSearchPaletteState();
+  State<ChainSearchPalette> createState() => _FaiSearchPaletteState();
 }
 
-class _FaiSearchPaletteState extends State<FaiSearchPalette> {
+class _FaiSearchPaletteState extends State<ChainSearchPalette> {
   final _query = TextEditingController();
   final _focus = FocusNode();
-  Future<List<FaiSearchHit>>? _dynamicFuture;
+  Future<List<ChainSearchHit>>? _dynamicFuture;
   int _highlight = 0;
 
   @override
@@ -92,7 +92,7 @@ class _FaiSearchPaletteState extends State<FaiSearchPalette> {
   /// Pull modules / store / flows in parallel so the palette
   /// is searchable as soon as the operator finishes typing the
   /// first character.
-  Future<List<FaiSearchHit>> _loadDynamic() async {
+  Future<List<ChainSearchHit>> _loadDynamic() async {
     final svc = HubService.instance;
     final l = AppLocalizations.of(context)!;
     final results = await Future.wait([
@@ -104,17 +104,17 @@ class _FaiSearchPaletteState extends State<FaiSearchPalette> {
     final store = results[1] as List<StoreItem>;
     final flows = results[2] as List<SavedFlow>;
 
-    final hits = <FaiSearchHit>[];
+    final hits = <ChainSearchHit>[];
     for (final m in modules) {
       hits.add(
-        FaiSearchHit(
+        ChainSearchHit(
           label: m.name,
           hint: l.searchInstalledModuleHint(m.version),
           icon: Icons.extension,
           group: l.searchGroupModules,
           onSelect: () {
             Navigator.pop(context);
-            FaiModuleSheet.show(context, m.name);
+            ChainModuleSheet.show(context, m.name);
           },
         ),
       );
@@ -123,7 +123,7 @@ class _FaiSearchPaletteState extends State<FaiSearchPalette> {
     final pagesGroup = l.searchGroupPages;
     for (final s in store) {
       hits.add(
-        FaiSearchHit(
+        ChainSearchHit(
           label: s.name,
           hint: s.taglineEn.isEmpty
               ? l.searchStoreHintWithCategory(
@@ -151,7 +151,7 @@ class _FaiSearchPaletteState extends State<FaiSearchPalette> {
     final flowsGroup = l.searchGroupFlows;
     for (final f in flows) {
       hits.add(
-        FaiSearchHit(
+        ChainSearchHit(
           label: f.name,
           hint: l.searchSavedFlowHint,
           icon: Icons.account_tree_outlined,
@@ -174,11 +174,11 @@ class _FaiSearchPaletteState extends State<FaiSearchPalette> {
   /// Filtered + grouped result list. Empty query returns the
   /// pages first then everything else, capped to 50 rows so the
   /// dialog stays scrollable.
-  List<FaiSearchHit> _resultsFor(List<FaiSearchHit> dynamic_, String raw) {
+  List<ChainSearchHit> _resultsFor(List<ChainSearchHit> dynamic_, String raw) {
     final query = raw.trim().toLowerCase();
     final all = [...widget.staticHits, ...dynamic_];
     if (query.isEmpty) return all.take(50).toList();
-    final scored = <(int, FaiSearchHit)>[];
+    final scored = <(int, ChainSearchHit)>[];
     for (final h in all) {
       final i = h.haystack.indexOf(query);
       if (i < 0) continue;
@@ -224,10 +224,10 @@ class _FaiSearchPaletteState extends State<FaiSearchPalette> {
       shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
       child: ConstrainedBox(
         constraints: const BoxConstraints(maxWidth: 640, maxHeight: 540),
-        child: FutureBuilder<List<FaiSearchHit>>(
+        child: FutureBuilder<List<ChainSearchHit>>(
           future: _dynamicFuture,
           builder: (context, snap) {
-            final dyn = snap.data ?? const <FaiSearchHit>[];
+            final dyn = snap.data ?? const <ChainSearchHit>[];
             return ValueListenableBuilder<TextEditingValue>(
               valueListenable: _query,
               builder: (_, value, _) {

lib/widgets/chain_settings_dialog.dart

@@ -1,4 +1,4 @@
-// FaiSettingsDialog — modal for changing the hub endpoint.
+// ChainSettingsDialog — modal for changing the hub endpoint.
 // Reads current values from HubService, persists on save via
 // HubService.reconnect.
 
@@ -14,25 +14,25 @@ import '../l10n/app_localizations.dart';
 import '../pages/welcome.dart' show showFaiDoc;
 import '../theme/theme.dart';
 import '../theme/tokens.dart';
-import 'fai_error_box.dart';
-import 'fai_pill.dart';
-import 'fai_system_ai_editor.dart';
+import 'chain_error_box.dart';
+import 'chain_pill.dart';
+import 'chain_system_ai_editor.dart';
 import 'theme_picker_grid.dart';
 
-class FaiSettingsDialog extends StatefulWidget {
-  const FaiSettingsDialog({super.key});
+class ChainSettingsDialog extends StatefulWidget {
+  const ChainSettingsDialog({super.key});
 
   /// Convenience launcher used from the sidebar gear icon.
   static Future<bool> show(BuildContext context) async {
     final ok = await showDialog<bool>(
       context: context,
-      builder: (_) => const FaiSettingsDialog(),
+      builder: (_) => const ChainSettingsDialog(),
     );
     return ok ?? false;
   }
 
   @override
-  State<FaiSettingsDialog> createState() => _FaiSettingsDialogState();
+  State<ChainSettingsDialog> createState() => _FaiSettingsDialogState();
 }
 
 /// Sidebar categories — every Settings panel belongs to exactly
@@ -40,7 +40,7 @@ class FaiSettingsDialog extends StatefulWidget {
 /// first-opened category.
 enum _Category { general, appearance, ai, integrations, security, maintenance }
 
-class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
+class _FaiSettingsDialogState extends State<ChainSettingsDialog> {
   late final TextEditingController _host;
   late final TextEditingController _port;
   bool _secure = false;
@@ -291,7 +291,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
       _saving = true;
       _channelToast = null;
     });
-    final r = await SystemActions.faiChannelSwitch(name);
+    final r = await SystemActions.chainChannelSwitch(name);
     if (!mounted) return;
     final l = AppLocalizations.of(context)!;
     setState(() {
@@ -384,10 +384,10 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
     };
     return SingleChildScrollView(
       padding: const EdgeInsets.fromLTRB(
-        FaiSpace.xl,
-        FaiSpace.xl,
-        FaiSpace.xl,
-        FaiSpace.lg,
+        ChainSpace.xl,
+        ChainSpace.xl,
+        ChainSpace.xl,
+        ChainSpace.lg,
       ),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
@@ -403,7 +403,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
     String? docSlug,
   }) {
     return Padding(
-      padding: const EdgeInsets.only(bottom: FaiSpace.lg),
+      padding: const EdgeInsets.only(bottom: ChainSpace.lg),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
@@ -455,7 +455,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
         ),
         autofocus: true,
       ),
-      const SizedBox(height: FaiSpace.md),
+      const SizedBox(height: ChainSpace.md),
       Row(
         children: [
           Expanded(
@@ -470,7 +470,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
               keyboardType: TextInputType.number,
             ),
           ),
-          const SizedBox(width: FaiSpace.md),
+          const SizedBox(width: ChainSpace.md),
           Expanded(
             flex: 3,
             child: SwitchListTile(
@@ -490,7 +490,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
         ],
       ),
       if (_error != null) ...[
-        const SizedBox(height: FaiSpace.md),
+        const SizedBox(height: ChainSpace.md),
         Text(
           _error!,
           style: theme.textTheme.bodySmall?.copyWith(
@@ -498,12 +498,12 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
           ),
         ),
       ],
-      const SizedBox(height: FaiSpace.md),
+      const SizedBox(height: ChainSpace.md),
       Container(
-        padding: const EdgeInsets.all(FaiSpace.sm),
+        padding: const EdgeInsets.all(ChainSpace.sm),
         decoration: BoxDecoration(
           color: theme.colorScheme.surfaceContainerHigh,
-          borderRadius: BorderRadius.circular(FaiRadius.sm),
+          borderRadius: BorderRadius.circular(ChainRadius.sm),
         ),
         child: Row(
           children: [
@@ -512,10 +512,10 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
               size: 14,
               color: theme.colorScheme.onSurfaceVariant,
             ),
-            const SizedBox(width: FaiSpace.sm),
+            const SizedBox(width: ChainSpace.sm),
             Text(
               _previewUrl(),
-              style: FaiTheme.mono(
+              style: ChainTheme.mono(
                 size: 11,
                 color: theme.colorScheme.onSurface,
               ),
@@ -524,7 +524,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
         ),
       ),
       if (_channels != null) ...[
-        const SizedBox(height: FaiSpace.xl),
+        const SizedBox(height: ChainSpace.xl),
         Text(
           l.channelsHeader,
           style: theme.textTheme.labelSmall?.copyWith(
@@ -540,7 +540,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
             color: theme.colorScheme.onSurfaceVariant,
           ),
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         for (final ch in _channels!.channels)
           _ChannelRow(
             channel: ch,
@@ -551,21 +551,21 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
                 ? null
                 : () => _runDaemon(
                     l.daemonActionEnableAutostart,
-                    () => SystemActions.faiDaemonEnable(ch.name),
+                    () => SystemActions.chainDaemonEnable(ch.name),
                   ),
             onDisableAutostart: _saving
                 ? null
                 : () => _runDaemon(
                     l.daemonActionDisableAutostart,
-                    () => SystemActions.faiDaemonDisable(ch.name),
+                    () => SystemActions.chainDaemonDisable(ch.name),
                   ),
           ),
         if (_channelToast != null) ...[
-          const SizedBox(height: FaiSpace.sm),
-          FaiErrorBox(text: _channelToast!, maxHeight: 200),
+          const SizedBox(height: ChainSpace.sm),
+          ChainErrorBox(text: _channelToast!, maxHeight: 200),
         ],
       ],
-      const SizedBox(height: FaiSpace.xl),
+      const SizedBox(height: ChainSpace.xl),
       const _DefaultScopePanel(),
     ];
   }
@@ -594,7 +594,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
         _SystemAiPanel(
           status: _aiStatus!,
           onEdit: () async {
-            final updated = await FaiSystemAiEditor.show(context, _aiStatus!);
+            final updated = await ChainSystemAiEditor.show(context, _aiStatus!);
             if (updated != null && mounted) {
               setState(() => _aiStatus = updated);
             }
@@ -612,7 +612,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
       ),
       if (_mcpClients == null)
         const Padding(
-          padding: EdgeInsets.symmetric(vertical: FaiSpace.md),
+          padding: EdgeInsets.symmetric(vertical: ChainSpace.md),
           child: Center(child: CircularProgressIndicator(strokeWidth: 2)),
         )
       else
@@ -622,7 +622,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
           onRemove: _removeMcpClient,
           onRefresh: _refreshMcpClients,
         ),
-      const SizedBox(height: FaiSpace.xl),
+      const SizedBox(height: ChainSpace.xl),
       if (_n8nEndpoints != null)
         _N8nEndpointsPanel(
           endpoints: _n8nEndpoints!,
@@ -646,7 +646,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
         onSave: _saveRegistryToken,
         onClear: _clearRegistryToken,
       ),
-      const SizedBox(height: FaiSpace.xl),
+      const SizedBox(height: ChainSpace.xl),
       _HubAuthTokenPanel(
         configuredChars: _hubAuthTokenChars,
         onSave: _saveHubAuthToken,
@@ -686,7 +686,7 @@ class _FaiSettingsDialogState extends State<FaiSettingsDialog> {
     return AlertDialog(
       title: Text(l.settingsTitle),
       shape: RoundedRectangleBorder(
-        borderRadius: BorderRadius.circular(FaiRadius.md),
+        borderRadius: BorderRadius.circular(ChainRadius.md),
       ),
       contentPadding: EdgeInsets.zero,
       content: ConstrainedBox(
@@ -770,15 +770,15 @@ class _ChannelRow extends StatelessWidget {
             channel.running ? Icons.circle : Icons.circle_outlined,
             size: 10,
             color: channel.running
-                ? FaiColors.success
+                ? ChainColors.success
                 : theme.colorScheme.outline,
           ),
-          const SizedBox(width: FaiSpace.sm),
+          const SizedBox(width: ChainSpace.sm),
           SizedBox(
             width: 88,
             child: Text(
               channel.name,
-              style: FaiTheme.mono(
+              style: ChainTheme.mono(
                 size: 11,
                 weight: active ? FontWeight.w600 : FontWeight.w400,
                 color: theme.colorScheme.onSurface,
@@ -789,7 +789,7 @@ class _ChannelRow extends StatelessWidget {
             width: 64,
             child: Text(
               ':${channel.port}',
-              style: FaiTheme.mono(
+              style: ChainTheme.mono(
                 size: 11,
                 color: theme.colorScheme.onSurfaceVariant,
               ),
@@ -805,10 +805,10 @@ class _ChannelRow extends StatelessWidget {
           ),
           if (active)
             Padding(
-              padding: const EdgeInsets.only(right: FaiSpace.sm),
-              child: FaiPill(
+              padding: const EdgeInsets.only(right: ChainSpace.sm),
+              child: ChainPill(
                 label: l.channelsActive,
-                tone: FaiPillTone.success,
+                tone: ChainPillTone.success,
               ),
             ),
           PopupMenuButton<String>(
@@ -876,7 +876,7 @@ class _MenuRow extends StatelessWidget {
     return Row(
       children: [
         Icon(icon, size: 14),
-        const SizedBox(width: FaiSpace.sm),
+        const SizedBox(width: ChainSpace.sm),
         Text(text),
       ],
     );
@@ -906,18 +906,18 @@ class _SystemAiPanel extends StatelessWidget {
                 fontSize: 10,
               ),
             ),
-            const SizedBox(width: FaiSpace.sm),
-            FaiPill(
+            const SizedBox(width: ChainSpace.sm),
+            ChainPill(
               label: status.enabled ? l.systemAiEnabled : l.systemAiOff,
-              tone: status.enabled ? FaiPillTone.success : FaiPillTone.neutral,
+              tone: status.enabled ? ChainPillTone.success : ChainPillTone.neutral,
             ),
             if (status.enabled) ...[
-              const SizedBox(width: FaiSpace.xs),
-              FaiPill(
+              const SizedBox(width: ChainSpace.xs),
+              ChainPill(
                 label: status.privacyMode,
                 tone: status.privacyMode == 'full'
-                    ? FaiPillTone.warning
-                    : FaiPillTone.neutral,
+                    ? ChainPillTone.warning
+                    : ChainPillTone.neutral,
               ),
             ],
             const Spacer(),
@@ -985,7 +985,7 @@ class _StatRow extends StatelessWidget {
             child: Text(
               value.isEmpty ? '—' : value,
               style: mono
-                  ? FaiTheme.mono(size: 11, color: theme.colorScheme.onSurface)
+                  ? ChainTheme.mono(size: 11, color: theme.colorScheme.onSurface)
                   : theme.textTheme.bodySmall,
             ),
           ),
@@ -1045,10 +1045,10 @@ class _McpClientsPanel extends StatelessWidget {
                 fontSize: 10,
               ),
             ),
-            const SizedBox(width: FaiSpace.sm),
-            FaiPill(
+            const SizedBox(width: ChainSpace.sm),
+            ChainPill(
               label: l.mcpServersCount(clients.length),
-              tone: FaiPillTone.neutral,
+              tone: ChainPillTone.neutral,
             ),
             const Spacer(),
             IconButton(
@@ -1075,10 +1075,10 @@ class _McpClientsPanel extends StatelessWidget {
             color: theme.colorScheme.onSurfaceVariant,
           ),
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         if (clients.isEmpty)
           Padding(
-            padding: const EdgeInsets.symmetric(vertical: FaiSpace.sm),
+            padding: const EdgeInsets.symmetric(vertical: ChainSpace.sm),
             child: Text(
               l.mcpEmpty,
               style: theme.textTheme.bodySmall?.copyWith(
@@ -1105,7 +1105,7 @@ class _McpClientRow extends StatelessWidget {
     final l = AppLocalizations.of(context)!;
     final ok = client.healthy;
     final dotColor = client.errorKind.isEmpty
-        ? (ok ? FaiColors.success : FaiColors.muted)
+        ? (ok ? ChainColors.success : ChainColors.muted)
         : theme.colorScheme.error;
     return Padding(
       padding: const EdgeInsets.symmetric(vertical: 4),
@@ -1116,7 +1116,7 @@ class _McpClientRow extends StatelessWidget {
             padding: const EdgeInsets.only(top: 6),
             child: Icon(Icons.circle, size: 8, color: dotColor),
           ),
-          const SizedBox(width: FaiSpace.sm),
+          const SizedBox(width: ChainSpace.sm),
           Expanded(
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
@@ -1125,28 +1125,28 @@ class _McpClientRow extends StatelessWidget {
                   children: [
                     Text(
                       client.name,
-                      style: FaiTheme.mono(
+                      style: ChainTheme.mono(
                         size: 12,
                         weight: FontWeight.w600,
                         color: theme.colorScheme.onSurface,
                       ),
                     ),
-                    const SizedBox(width: FaiSpace.sm),
+                    const SizedBox(width: ChainSpace.sm),
                     if (client.toolCount > 0)
-                      FaiPill(
+                      ChainPill(
                         label: l.mcpToolsCount(client.toolCount),
-                        tone: FaiPillTone.success,
+                        tone: ChainPillTone.success,
                       )
                     else if (client.errorKind.isNotEmpty)
-                      FaiPill(
+                      ChainPill(
                         label: client.errorKind,
-                        tone: FaiPillTone.danger,
+                        tone: ChainPillTone.danger,
                       ),
                   ],
                 ),
                 Text(
                   client.endpoint,
-                  style: FaiTheme.mono(
+                  style: ChainTheme.mono(
                     size: 10,
                     color: theme.colorScheme.onSurfaceVariant,
                   ),
@@ -1234,7 +1234,7 @@ class _AddMcpClientDialogState extends State<_AddMcpClientDialog> {
                 color: theme.colorScheme.onSurfaceVariant,
               ),
             ),
-            const SizedBox(height: FaiSpace.md),
+            const SizedBox(height: ChainSpace.md),
             // Curated suggestions from the official Anthropic
             // MCP servers + a few community staples. Click a
             // chip to pre-fill the form. The operator still
@@ -1249,8 +1249,8 @@ class _AddMcpClientDialogState extends State<_AddMcpClientDialog> {
             ),
             const SizedBox(height: 6),
             Wrap(
-              spacing: FaiSpace.xs,
-              runSpacing: FaiSpace.xs,
+              spacing: ChainSpace.xs,
+              runSpacing: ChainSpace.xs,
               children: [
                 for (final s in _kMcpSuggestions)
                   ActionChip(
@@ -1260,7 +1260,7 @@ class _AddMcpClientDialogState extends State<_AddMcpClientDialog> {
                   ),
               ],
             ),
-            const Divider(height: FaiSpace.xl),
+            const Divider(height: ChainSpace.xl),
             TextField(
               controller: _name,
               autofocus: true,
@@ -1271,7 +1271,7 @@ class _AddMcpClientDialogState extends State<_AddMcpClientDialog> {
                 isDense: true,
               ),
             ),
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
             TextField(
               controller: _endpoint,
               decoration: InputDecoration(
@@ -1281,7 +1281,7 @@ class _AddMcpClientDialogState extends State<_AddMcpClientDialog> {
                 isDense: true,
               ),
             ),
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
             TextField(
               controller: _apiKey,
               decoration: InputDecoration(
@@ -1292,7 +1292,7 @@ class _AddMcpClientDialogState extends State<_AddMcpClientDialog> {
                 isDense: true,
               ),
             ),
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
             TextField(
               controller: _desc,
               decoration: InputDecoration(
@@ -1377,10 +1377,10 @@ class _N8nEndpointsPanel extends StatelessWidget {
                 fontSize: 10,
               ),
             ),
-            const SizedBox(width: FaiSpace.sm),
-            FaiPill(
+            const SizedBox(width: ChainSpace.sm),
+            ChainPill(
               label: l.n8nEndpointsCount(endpoints.length),
-              tone: FaiPillTone.neutral,
+              tone: ChainPillTone.neutral,
             ),
             const Spacer(),
             IconButton(
@@ -1407,10 +1407,10 @@ class _N8nEndpointsPanel extends StatelessWidget {
             color: theme.colorScheme.onSurfaceVariant,
           ),
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         if (endpoints.isEmpty)
           Padding(
-            padding: const EdgeInsets.symmetric(vertical: FaiSpace.sm),
+            padding: const EdgeInsets.symmetric(vertical: ChainSpace.sm),
             child: Text(
               l.n8nEmpty,
               style: theme.textTheme.bodySmall?.copyWith(
@@ -1437,7 +1437,7 @@ class _N8nEndpointRow extends StatelessWidget {
     final l = AppLocalizations.of(context)!;
     final ok = endpoint.healthy;
     final dotColor = endpoint.errorKind.isEmpty
-        ? (ok ? FaiColors.success : FaiColors.muted)
+        ? (ok ? ChainColors.success : ChainColors.muted)
         : theme.colorScheme.error;
     return Padding(
       padding: const EdgeInsets.symmetric(vertical: 4),
@@ -1448,7 +1448,7 @@ class _N8nEndpointRow extends StatelessWidget {
             padding: const EdgeInsets.only(top: 6),
             child: Icon(Icons.circle, size: 8, color: dotColor),
           ),
-          const SizedBox(width: FaiSpace.sm),
+          const SizedBox(width: ChainSpace.sm),
           Expanded(
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
@@ -1457,28 +1457,28 @@ class _N8nEndpointRow extends StatelessWidget {
                   children: [
                     Text(
                       endpoint.name,
-                      style: FaiTheme.mono(
+                      style: ChainTheme.mono(
                         size: 12,
                         weight: FontWeight.w600,
                         color: theme.colorScheme.onSurface,
                       ),
                     ),
-                    const SizedBox(width: FaiSpace.sm),
+                    const SizedBox(width: ChainSpace.sm),
                     if (endpoint.workflowCount > 0)
-                      FaiPill(
+                      ChainPill(
                         label: l.n8nWorkflowsCount(endpoint.workflowCount),
-                        tone: FaiPillTone.success,
+                        tone: ChainPillTone.success,
                       )
                     else if (endpoint.errorKind.isNotEmpty)
-                      FaiPill(
+                      ChainPill(
                         label: endpoint.errorKind,
-                        tone: FaiPillTone.danger,
+                        tone: ChainPillTone.danger,
                       ),
                   ],
                 ),
                 Text(
                   endpoint.baseUrl,
-                  style: FaiTheme.mono(
+                  style: ChainTheme.mono(
                     size: 10,
                     color: theme.colorScheme.onSurfaceVariant,
                   ),
@@ -1554,7 +1554,7 @@ class _AddN8nEndpointDialogState extends State<_AddN8nEndpointDialog> {
                 color: theme.colorScheme.onSurfaceVariant,
               ),
             ),
-            const SizedBox(height: FaiSpace.md),
+            const SizedBox(height: ChainSpace.md),
             TextField(
               controller: _name,
               autofocus: true,
@@ -1565,7 +1565,7 @@ class _AddN8nEndpointDialogState extends State<_AddN8nEndpointDialog> {
                 isDense: true,
               ),
             ),
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
             TextField(
               controller: _baseUrl,
               decoration: InputDecoration(
@@ -1575,7 +1575,7 @@ class _AddN8nEndpointDialogState extends State<_AddN8nEndpointDialog> {
                 isDense: true,
               ),
             ),
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
             TextField(
               controller: _apiKey,
               decoration: InputDecoration(
@@ -1586,7 +1586,7 @@ class _AddN8nEndpointDialogState extends State<_AddN8nEndpointDialog> {
                 isDense: true,
               ),
             ),
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
             TextField(
               controller: _desc,
               decoration: InputDecoration(
@@ -1718,7 +1718,7 @@ class _MaintenancePanelState extends State<_MaintenancePanel> {
       _resetting = true;
       _resultText = null;
     });
-    final r = await SystemActions.faiReset(
+    final r = await SystemActions.chainReset(
       keepModules: _keepModules,
       keepData: _keepData,
     );
@@ -1755,7 +1755,7 @@ class _MaintenancePanelState extends State<_MaintenancePanel> {
             color: theme.colorScheme.onSurfaceVariant,
           ),
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         CheckboxListTile(
           contentPadding: EdgeInsets.zero,
           dense: true,
@@ -1788,7 +1788,7 @@ class _MaintenancePanelState extends State<_MaintenancePanel> {
             ),
           ),
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         Row(
           children: [
             FilledButton.icon(
@@ -1813,8 +1813,8 @@ class _MaintenancePanelState extends State<_MaintenancePanel> {
           ],
         ),
         if (_resultText != null) ...[
-          const SizedBox(height: FaiSpace.sm),
-          FaiErrorBox(text: _resultText!, isError: !_resultOk, maxHeight: 240),
+          const SizedBox(height: ChainSpace.sm),
+          ChainErrorBox(text: _resultText!, isError: !_resultOk, maxHeight: 240),
         ],
       ],
     );
@@ -1891,7 +1891,7 @@ class _RegistryCredentialsPanelState extends State<_RegistryCredentialsPanel> {
             color: theme.colorScheme.onSurfaceVariant,
           ),
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         Row(
           children: [
             Icon(
@@ -1901,7 +1901,7 @@ class _RegistryCredentialsPanelState extends State<_RegistryCredentialsPanel> {
                   ? theme.colorScheme.primary
                   : theme.colorScheme.onSurfaceVariant,
             ),
-            const SizedBox(width: FaiSpace.xs),
+            const SizedBox(width: ChainSpace.xs),
             Text(
               isConfigured
                   ? l.registryTokenStatusConfigured(widget.configuredChars!)
@@ -1925,7 +1925,7 @@ class _RegistryCredentialsPanelState extends State<_RegistryCredentialsPanel> {
               ),
           ],
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         Row(
           children: [
             Expanded(
@@ -1947,7 +1947,7 @@ class _RegistryCredentialsPanelState extends State<_RegistryCredentialsPanel> {
                 ),
               ),
             ),
-            const SizedBox(width: FaiSpace.sm),
+            const SizedBox(width: ChainSpace.sm),
             FilledButton.icon(
               icon: const Icon(Icons.save_outlined, size: 14),
               label: Text(l.registryTokenSaveButton),
@@ -2040,7 +2040,7 @@ class _HubAuthTokenPanelState extends State<_HubAuthTokenPanel> {
             color: theme.colorScheme.onSurfaceVariant,
           ),
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         Row(
           children: [
             Icon(
@@ -2050,7 +2050,7 @@ class _HubAuthTokenPanelState extends State<_HubAuthTokenPanel> {
                   ? theme.colorScheme.primary
                   : theme.colorScheme.onSurfaceVariant,
             ),
-            const SizedBox(width: FaiSpace.xs),
+            const SizedBox(width: ChainSpace.xs),
             Text(
               isConfigured
                   ? l.hubAuthTokenStatusConfigured(widget.configuredChars!)
@@ -2074,7 +2074,7 @@ class _HubAuthTokenPanelState extends State<_HubAuthTokenPanel> {
               ),
           ],
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         Row(
           children: [
             Expanded(
@@ -2096,7 +2096,7 @@ class _HubAuthTokenPanelState extends State<_HubAuthTokenPanel> {
                 ),
               ),
             ),
-            const SizedBox(width: FaiSpace.sm),
+            const SizedBox(width: ChainSpace.sm),
             FilledButton.icon(
               icon: const Icon(Icons.save_outlined, size: 14),
               label: Text(l.hubAuthTokenSaveButton),
@@ -2410,10 +2410,10 @@ class _DefaultScopePanelState extends State<_DefaultScopePanel> {
             color: theme.colorScheme.onSurfaceVariant,
           ),
         ),
-        const SizedBox(height: FaiSpace.sm),
+        const SizedBox(height: ChainSpace.sm),
         if (_loading)
           const Padding(
-            padding: EdgeInsets.symmetric(vertical: FaiSpace.sm),
+            padding: EdgeInsets.symmetric(vertical: ChainSpace.sm),
             child: SizedBox(
               height: 16,
               width: 16,
@@ -2438,7 +2438,7 @@ class _DefaultScopePanelState extends State<_DefaultScopePanel> {
               onDown: () => _moveDown(i),
               onRemove: () => _removeAt(i),
             ),
-          const SizedBox(height: FaiSpace.sm),
+          const SizedBox(height: ChainSpace.sm),
           Row(
             children: [
               Expanded(
@@ -2453,7 +2453,7 @@ class _DefaultScopePanelState extends State<_DefaultScopePanel> {
                   onSubmitted: _saving ? null : _addEntry,
                 ),
               ),
-              const SizedBox(width: FaiSpace.sm),
+              const SizedBox(width: ChainSpace.sm),
               FilledButton.icon(
                 icon: const Icon(Icons.add, size: 14),
                 label: Text(l.defaultScopeAddButton),
@@ -2464,7 +2464,7 @@ class _DefaultScopePanelState extends State<_DefaultScopePanel> {
             ],
           ),
           if (unusedSuggestions.isNotEmpty) ...[
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
             Text(
               l.defaultScopeSuggestions,
               style: theme.textTheme.bodySmall?.copyWith(
@@ -2474,7 +2474,7 @@ class _DefaultScopePanelState extends State<_DefaultScopePanel> {
             ),
             const SizedBox(height: 4),
             Wrap(
-              spacing: FaiSpace.xs,
+              spacing: ChainSpace.xs,
               runSpacing: 4,
               children: [
                 for (final s in unusedSuggestions)
@@ -2489,7 +2489,7 @@ class _DefaultScopePanelState extends State<_DefaultScopePanel> {
             ),
           ],
           if (_error != null) ...[
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
             Text(
               _error!,
               style: theme.textTheme.bodySmall?.copyWith(
@@ -2603,7 +2603,7 @@ class _Sidebar extends StatelessWidget {
       child: Container(
         color: theme.colorScheme.surfaceContainer,
         child: ListView(
-          padding: const EdgeInsets.symmetric(vertical: FaiSpace.lg),
+          padding: const EdgeInsets.symmetric(vertical: ChainSpace.lg),
           children: [
             for (final (cat, icon, label) in items)
               _SidebarRow(
@@ -2639,24 +2639,24 @@ class _SidebarRow extends StatelessWidget {
         ? theme.colorScheme.onSurface
         : theme.colorScheme.onSurfaceVariant;
     return Padding(
-      padding: const EdgeInsets.symmetric(horizontal: FaiSpace.sm, vertical: 2),
+      padding: const EdgeInsets.symmetric(horizontal: ChainSpace.sm, vertical: 2),
       child: Material(
         color: selected
             ? theme.colorScheme.primary.withValues(alpha: 0.14)
             : Colors.transparent,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         child: InkWell(
           onTap: onTap,
-          borderRadius: BorderRadius.circular(FaiRadius.sm),
+          borderRadius: BorderRadius.circular(ChainRadius.sm),
           child: Padding(
             padding: const EdgeInsets.symmetric(
-              horizontal: FaiSpace.md,
+              horizontal: ChainSpace.md,
               vertical: 8,
             ),
             child: Row(
               children: [
                 Icon(icon, size: 16, color: fg),
-                const SizedBox(width: FaiSpace.sm),
+                const SizedBox(width: ChainSpace.sm),
                 Text(
                   label,
                   style: theme.textTheme.bodyMedium?.copyWith(

lib/widgets/chain_status_dot.dart

@@ -1,11 +1,11 @@
-// FaiStatusDot — small pulsing dot used as a "live" indicator.
+// ChainStatusDot — small pulsing dot used as a "live" indicator.
 // Goes still when [pulsing] is false, breathes gently when true.
 
 import 'package:flutter/material.dart';
 
 import '../theme/tokens.dart';
 
-class FaiStatusDot extends StatefulWidget {
+class ChainStatusDot extends StatefulWidget {
   final Color color;
 
   /// When true, the dot fades between full and 30% opacity.
@@ -14,7 +14,7 @@ class FaiStatusDot extends StatefulWidget {
 
   final double size;
 
-  const FaiStatusDot({
+  const ChainStatusDot({
     super.key,
     required this.color,
     this.pulsing = false,
@@ -22,10 +22,10 @@ class FaiStatusDot extends StatefulWidget {
   });
 
   @override
-  State<FaiStatusDot> createState() => _FaiStatusDotState();
+  State<ChainStatusDot> createState() => _FaiStatusDotState();
 }
 
-class _FaiStatusDotState extends State<FaiStatusDot>
+class _FaiStatusDotState extends State<ChainStatusDot>
     with SingleTickerProviderStateMixin {
   late final AnimationController _ctrl;
 
@@ -40,7 +40,7 @@ class _FaiStatusDotState extends State<FaiStatusDot>
   }
 
   @override
-  void didUpdateWidget(covariant FaiStatusDot old) {
+  void didUpdateWidget(covariant ChainStatusDot old) {
     super.didUpdateWidget(old);
     if (widget.pulsing && !_ctrl.isAnimating) {
       _ctrl.repeat(reverse: true);
@@ -86,10 +86,10 @@ class _FaiStatusDotState extends State<FaiStatusDot>
 }
 
 /// Convenience presets.
-class FaiStatusDots {
-  FaiStatusDots._();
+class ChainStatusDots {
+  ChainStatusDots._();
   static Widget live() =>
-      const FaiStatusDot(color: FaiColors.success, pulsing: true);
-  static Widget idle() => const FaiStatusDot(color: FaiColors.muted);
-  static Widget down() => const FaiStatusDot(color: FaiColors.danger);
+      const ChainStatusDot(color: ChainColors.success, pulsing: true);
+  static Widget idle() => const ChainStatusDot(color: ChainColors.muted);
+  static Widget down() => const ChainStatusDot(color: ChainColors.danger);
 }

lib/widgets/chain_system_ai_editor.dart

@@ -1,4 +1,4 @@
-// FaiSystemAiEditor — modal for configuring the hub-internal
+// ChainSystemAiEditor — modal for configuring the hub-internal
 // System AI from inside Studio. Mirrors the YAML block but with
 // provider presets, in-place explainers, and a "Test connection"
 // button. On save, calls HubAdmin.UpdateSystemAi which both
@@ -11,10 +11,10 @@ import '../data/hub.dart';
 import '../l10n/app_localizations.dart';
 import '../theme/theme.dart';
 import '../theme/tokens.dart';
-import 'fai_pill.dart';
+import 'chain_pill.dart';
 
 /// Provider preset metadata kept in sync with
-/// `fai_hub::operator_config::SystemLlmProvider`. Anything that
+/// `chain_hub::operator_config::SystemLlmProvider`. Anything that
 /// is operator-visible (label, description, default endpoint,
 /// suggested env-var) lives here so the dropdown self-explains
 /// without needing to read the source.
@@ -108,10 +108,10 @@ class _ProviderPreset {
   }
 }
 
-class FaiSystemAiEditor extends StatefulWidget {
+class ChainSystemAiEditor extends StatefulWidget {
   final SystemAiStatus initial;
 
-  const FaiSystemAiEditor({super.key, required this.initial});
+  const ChainSystemAiEditor({super.key, required this.initial});
 
   /// Convenience launcher. Returns the new status when the
   /// operator saved, null on cancel.
@@ -121,15 +121,15 @@ class FaiSystemAiEditor extends StatefulWidget {
   ) {
     return showDialog<SystemAiStatus>(
       context: context,
-      builder: (_) => FaiSystemAiEditor(initial: initial),
+      builder: (_) => ChainSystemAiEditor(initial: initial),
     );
   }
 
   @override
-  State<FaiSystemAiEditor> createState() => _FaiSystemAiEditorState();
+  State<ChainSystemAiEditor> createState() => _FaiSystemAiEditorState();
 }
 
-class _FaiSystemAiEditorState extends State<FaiSystemAiEditor> {
+class _FaiSystemAiEditorState extends State<ChainSystemAiEditor> {
   late _ProviderPreset _preset;
   late final TextEditingController _endpoint;
   late final TextEditingController _model;
@@ -365,11 +365,11 @@ class _FaiSystemAiEditorState extends State<FaiSystemAiEditor> {
     return AlertDialog(
       title: Text(l.systemAiTitle),
       shape: RoundedRectangleBorder(
-        borderRadius: BorderRadius.circular(FaiRadius.md),
+        borderRadius: BorderRadius.circular(ChainRadius.md),
       ),
       contentPadding: const EdgeInsets.symmetric(
-        horizontal: FaiSpace.xl,
-        vertical: FaiSpace.lg,
+        horizontal: ChainSpace.xl,
+        vertical: ChainSpace.lg,
       ),
       content: ConstrainedBox(
         constraints: const BoxConstraints(maxWidth: 520, maxHeight: 600),
@@ -385,10 +385,10 @@ class _FaiSystemAiEditorState extends State<FaiSystemAiEditor> {
                 ),
               ),
               if (_hw != null) ...[
-                const SizedBox(height: FaiSpace.sm),
+                const SizedBox(height: ChainSpace.sm),
                 _HardwareBanner(hw: _hw!, lastReviewed: _curated?.lastReviewed),
               ],
-              const SizedBox(height: FaiSpace.lg),
+              const SizedBox(height: ChainSpace.lg),
               _ProviderDropdown(value: _preset, onChanged: _onProviderChanged),
               const SizedBox(height: 4),
               Text(
@@ -397,17 +397,17 @@ class _FaiSystemAiEditorState extends State<FaiSystemAiEditor> {
                   color: theme.colorScheme.onSurfaceVariant,
                 ),
               ),
-              const SizedBox(height: FaiSpace.md),
+              const SizedBox(height: ChainSpace.md),
               TextField(
                 controller: _endpoint,
-                style: FaiTheme.mono(size: 12),
+                style: ChainTheme.mono(size: 12),
                 decoration: InputDecoration(
                   labelText: l.systemAiEndpointLabel,
                   border: const OutlineInputBorder(),
                   isDense: true,
                 ),
               ),
-              const SizedBox(height: FaiSpace.md),
+              const SizedBox(height: ChainSpace.md),
               _ModelPicker(
                 controller: _model,
                 preset: _preset,
@@ -424,10 +424,10 @@ class _FaiSystemAiEditorState extends State<FaiSystemAiEditor> {
                     ? null
                     : _pullModel,
               ),
-              const SizedBox(height: FaiSpace.md),
+              const SizedBox(height: ChainSpace.md),
               TextField(
                 controller: _apiKeyEnv,
-                style: FaiTheme.mono(size: 12),
+                style: ChainTheme.mono(size: 12),
                 decoration: InputDecoration(
                   labelText: _preset.wire == 'openai'
                       ? l.systemAiApiKeyRequired
@@ -445,20 +445,20 @@ class _FaiSystemAiEditorState extends State<FaiSystemAiEditor> {
                   color: theme.colorScheme.onSurfaceVariant,
                 ),
               ),
-              const SizedBox(height: FaiSpace.lg),
+              const SizedBox(height: ChainSpace.lg),
               _PrivacyModeChips(
                 value: _privacyMode,
                 onChanged: (v) => setState(() => _privacyMode = v),
               ),
               if (widget.initial.cacheCount > 0) ...[
-                const SizedBox(height: FaiSpace.md),
+                const SizedBox(height: ChainSpace.md),
                 _CacheStatusRow(
                   cacheCount: widget.initial.cacheCount,
                   onClear: _saving || _testing ? null : _clearCache,
                 ),
               ],
               if (_error != null) ...[
-                const SizedBox(height: FaiSpace.md),
+                const SizedBox(height: ChainSpace.md),
                 Text(
                   _error!,
                   style: theme.textTheme.bodySmall?.copyWith(
@@ -467,7 +467,7 @@ class _FaiSystemAiEditorState extends State<FaiSystemAiEditor> {
                 ),
               ],
               if (_testResult != null) ...[
-                const SizedBox(height: FaiSpace.md),
+                const SizedBox(height: ChainSpace.md),
                 _TestResultPanel(result: _testResult!),
               ],
             ],
@@ -573,11 +573,11 @@ class _PrivacyModeChips extends StatelessWidget {
           for (final (wire, label, desc) in modes)
             InkWell(
               onTap: () => onChanged(wire),
-              borderRadius: BorderRadius.circular(FaiRadius.sm),
+              borderRadius: BorderRadius.circular(ChainRadius.sm),
               child: Padding(
                 padding: const EdgeInsets.symmetric(
-                  vertical: FaiSpace.sm,
-                  horizontal: FaiSpace.sm,
+                  vertical: ChainSpace.sm,
+                  horizontal: ChainSpace.sm,
                 ),
                 child: Row(
                   children: [
@@ -616,13 +616,13 @@ class _TestResultPanel extends StatelessWidget {
     final theme = Theme.of(context);
     final l = AppLocalizations.of(context)!;
     final ok = result.isSuccess;
-    final color = ok ? FaiColors.success : theme.colorScheme.error;
+    final color = ok ? ChainColors.success : theme.colorScheme.error;
     return Container(
       width: double.infinity,
-      padding: const EdgeInsets.all(FaiSpace.md),
+      padding: const EdgeInsets.all(ChainSpace.md),
       decoration: BoxDecoration(
         color: theme.colorScheme.surfaceContainerHigh,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         border: Border.all(color: color.withValues(alpha: 0.3)),
       ),
       child: Column(
@@ -635,16 +635,16 @@ class _TestResultPanel extends StatelessWidget {
                 size: 14,
                 color: color,
               ),
-              const SizedBox(width: FaiSpace.xs),
+              const SizedBox(width: ChainSpace.xs),
               Text(
                 ok ? l.systemAiConnectionOk : l.systemAiConnectionFailed,
                 style: theme.textTheme.bodyMedium?.copyWith(color: color),
               ),
               const Spacer(),
               if (ok && result.latencyMs > 0)
-                FaiPill(
+                ChainPill(
                   label: '${result.latencyMs} ms',
-                  tone: FaiPillTone.neutral,
+                  tone: ChainPillTone.neutral,
                   monospace: true,
                 ),
             ],
@@ -652,10 +652,10 @@ class _TestResultPanel extends StatelessWidget {
           const SizedBox(height: 4),
           SelectableText(
             ok ? l.systemAiReplyPrefix(result.text) : result.text,
-            style: FaiTheme.mono(size: 11, color: theme.colorScheme.onSurface),
+            style: ChainTheme.mono(size: 11, color: theme.colorScheme.onSurface),
           ),
           if (!ok && result.fixHint(l).isNotEmpty) ...[
-            const SizedBox(height: FaiSpace.xs),
+            const SizedBox(height: ChainSpace.xs),
             Text(
               result.fixHint(l),
               style: theme.textTheme.bodySmall?.copyWith(
@@ -720,7 +720,7 @@ class _ModelPicker extends StatelessWidget {
                 valueListenable: controller,
                 builder: (_, _, _) => TextField(
                   controller: controller,
-                  style: FaiTheme.mono(size: 12),
+                  style: ChainTheme.mono(size: 12),
                   decoration: InputDecoration(
                     labelText: l.systemAiModelLabel,
                     hintText: preset.modelHint.isEmpty
@@ -738,7 +738,7 @@ class _ModelPicker extends StatelessWidget {
                 ),
               ),
             ),
-            const SizedBox(width: FaiSpace.sm),
+            const SizedBox(width: ChainSpace.sm),
             OutlinedButton.icon(
               onPressed: onRefresh,
               icon: loading
@@ -751,7 +751,7 @@ class _ModelPicker extends StatelessWidget {
               label: Text(l.systemAiRefresh),
             ),
             if (_isOllama) ...[
-              const SizedBox(width: FaiSpace.sm),
+              const SizedBox(width: ChainSpace.sm),
               OutlinedButton.icon(
                 onPressed: onPull,
                 icon: pulling
@@ -776,7 +776,7 @@ class _ModelPicker extends StatelessWidget {
           ),
         ],
         if (models != null) ...[
-          const SizedBox(height: FaiSpace.sm),
+          const SizedBox(height: ChainSpace.sm),
           if (models!.isEmpty)
             Text(
               _isOllama ? l.systemAiNoModelsOllama : l.systemAiNoModelsGeneric,
@@ -786,8 +786,8 @@ class _ModelPicker extends StatelessWidget {
             )
           else ...[
             Wrap(
-              spacing: FaiSpace.xs,
-              runSpacing: FaiSpace.xs,
+              spacing: ChainSpace.xs,
+              runSpacing: ChainSpace.xs,
               children: [
                 for (final id in _sortedBySuitability(
                   models!,
@@ -850,13 +850,13 @@ extension _SuitabilityCopy on _Suitability {
   Color color(ColorScheme cs) {
     switch (this) {
       case _Suitability.recommended:
-        return FaiColors.success;
+        return ChainColors.success;
       case _Suitability.balanced:
         return cs.primary;
       case _Suitability.small:
-        return FaiColors.warning;
+        return ChainColors.warning;
       case _Suitability.large:
-        return FaiColors.warning;
+        return ChainColors.warning;
       case _Suitability.huge:
         return cs.error;
       case _Suitability.unknown:
@@ -1005,7 +1005,7 @@ class _ModelChip extends StatelessWidget {
           size: suitability == _Suitability.recommended ? 14 : 9,
           color: color,
         ),
-        label: Text(id, style: FaiTheme.mono(size: 11)),
+        label: Text(id, style: ChainTheme.mono(size: 11)),
         side: BorderSide(color: color.withValues(alpha: 0.4)),
         onPressed: onTap,
       ),
@@ -1030,10 +1030,10 @@ class _HardwareBanner extends StatelessWidget {
         ? l.systemAiHwReviewed(lastReviewed!)
         : '';
     return Container(
-      padding: const EdgeInsets.symmetric(horizontal: FaiSpace.sm, vertical: 6),
+      padding: const EdgeInsets.symmetric(horizontal: ChainSpace.sm, vertical: 6),
       decoration: BoxDecoration(
         color: theme.colorScheme.surfaceContainerHigh,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         border: Border.all(color: theme.colorScheme.outlineVariant),
       ),
       child: Row(
@@ -1067,7 +1067,7 @@ class _SuitabilityLegend extends StatelessWidget {
     final theme = Theme.of(context);
     final l = AppLocalizations.of(context)!;
     Widget dot(Color c, String label) => Padding(
-      padding: const EdgeInsets.only(right: FaiSpace.md),
+      padding: const EdgeInsets.only(right: ChainSpace.md),
       child: Row(
         mainAxisSize: MainAxisSize.min,
         children: [
@@ -1090,11 +1090,11 @@ class _SuitabilityLegend extends StatelessWidget {
       crossAxisAlignment: WrapCrossAlignment.center,
       children: [
         Padding(
-          padding: const EdgeInsets.only(right: FaiSpace.md),
+          padding: const EdgeInsets.only(right: ChainSpace.md),
           child: Row(
             mainAxisSize: MainAxisSize.min,
             children: [
-              Icon(Icons.star, size: 11, color: FaiColors.success),
+              Icon(Icons.star, size: 11, color: ChainColors.success),
               const SizedBox(width: 4),
               Text(
                 l.systemAiLegendRecommended(tierTag),
@@ -1107,7 +1107,7 @@ class _SuitabilityLegend extends StatelessWidget {
           ),
         ),
         dot(theme.colorScheme.primary, l.systemAiLegendBalanced),
-        dot(FaiColors.warning, l.systemAiLegendSmallLarge),
+        dot(ChainColors.warning, l.systemAiLegendSmallLarge),
         dot(theme.colorScheme.error, l.systemAiLegendHuge),
         dot(theme.colorScheme.outline, l.systemAiLegendUnknown),
       ],
@@ -1131,10 +1131,10 @@ class _CacheStatusRow extends StatelessWidget {
     final theme = Theme.of(context);
     final l = AppLocalizations.of(context)!;
     return Container(
-      padding: const EdgeInsets.symmetric(horizontal: FaiSpace.sm, vertical: 6),
+      padding: const EdgeInsets.symmetric(horizontal: ChainSpace.sm, vertical: 6),
       decoration: BoxDecoration(
         color: theme.colorScheme.surfaceContainerHigh,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         border: Border.all(color: theme.colorScheme.outlineVariant),
       ),
       child: Row(

lib/widgets/theme_picker_grid.dart

@@ -55,7 +55,7 @@ class _ThemePickerGridState extends State<ThemePickerGrid> {
       builder: (context, snap) {
         if (snap.connectionState != ConnectionState.done) {
           return const Padding(
-            padding: EdgeInsets.symmetric(vertical: FaiSpace.sm),
+            padding: EdgeInsets.symmetric(vertical: ChainSpace.sm),
             child: SizedBox(
               width: 14,
               height: 14,
@@ -85,7 +85,7 @@ class _ThemePickerGridState extends State<ThemePickerGrid> {
                 _customTile(theme, l, active),
               ],
             ),
-            const SizedBox(height: FaiSpace.sm),
+            const SizedBox(height: ChainSpace.sm),
             Text(
               l.themePluginHint,
               style: theme.textTheme.bodySmall?.copyWith(
@@ -248,13 +248,13 @@ class _Tile extends StatelessWidget {
       height: 76,
       child: Material(
         color: theme.colorScheme.surfaceContainerHigh,
-        borderRadius: BorderRadius.circular(FaiRadius.sm),
+        borderRadius: BorderRadius.circular(ChainRadius.sm),
         child: InkWell(
           onTap: onTap,
-          borderRadius: BorderRadius.circular(FaiRadius.sm),
+          borderRadius: BorderRadius.circular(ChainRadius.sm),
           child: Container(
             decoration: BoxDecoration(
-              borderRadius: BorderRadius.circular(FaiRadius.sm),
+              borderRadius: BorderRadius.circular(ChainRadius.sm),
               border: Border.all(
                 color: selected
                     ? theme.colorScheme.primary
@@ -432,7 +432,7 @@ class _ColorPickerDialogState extends State<_ColorPickerDialog> {
                   ),
               ],
             ),
-            const SizedBox(height: FaiSpace.md),
+            const SizedBox(height: ChainSpace.md),
             TextField(
               controller: _hex,
               decoration: InputDecoration(
@@ -444,7 +444,7 @@ class _ColorPickerDialogState extends State<_ColorPickerDialog> {
               onChanged: _commitHex,
               onSubmitted: _commitHex,
             ),
-            const SizedBox(height: FaiSpace.md),
+            const SizedBox(height: ChainSpace.md),
             Text(l.themePluginCustomPreview, style: theme.textTheme.labelSmall),
             const SizedBox(height: 6),
             Row(

lib/widgets/widgets.dart

@@ -4,17 +4,17 @@
 // primitives directly — no Material `Card` / generic `Container`
 // soup in page code.
 
-export 'fai_binary_recovery.dart';
-export 'fai_card.dart';
-export 'fai_data_row.dart';
-export 'fai_delta_mark.dart';
-export 'fai_empty_state.dart';
-export 'fai_en_badge.dart';
-export 'fai_error_box.dart';
-export 'fai_flow_output.dart';
-export 'fai_log_viewer.dart';
-export 'fai_module_sheet.dart';
-export 'fai_pill.dart';
-export 'fai_settings_dialog.dart';
-export 'fai_status_dot.dart';
-export 'fai_system_ai_editor.dart';
+export 'chain_binary_recovery.dart';
+export 'chain_card.dart';
+export 'chain_data_row.dart';
+export 'chain_delta_mark.dart';
+export 'chain_empty_state.dart';
+export 'chain_en_badge.dart';
+export 'chain_error_box.dart';
+export 'chain_flow_output.dart';
+export 'chain_log_viewer.dart';
+export 'chain_module_sheet.dart';
+export 'chain_pill.dart';
+export 'chain_settings_dialog.dart';
+export 'chain_status_dot.dart';
+export 'chain_system_ai_editor.dart';