feat(ui): warm-minimalism redesign — design tokens + 6 primitives + animated ∆

Replaces the Material-default look with a deliberate visual
language. Single accent (sky-cyan), Inter + JetBrains Mono via
google_fonts, dense rows over puffy cards, micro-interactions
under 250ms. Dark-first, light reaches parity.

New foundation under lib/theme/:
- tokens.dart   FaiColors / FaiSpace / FaiRadius / FaiMotion
- theme.dart    ColorScheme + typography + component themes for
                light and dark, plus FaiTheme.mono helper for
                technical strings (IDs, paths, capability refs).

Six primitives under lib/widgets/:
- FaiCard            flat card, optional accent stripe (top or
                     left). No shadows.
- FaiPill            small inline label with five tones
                     (neutral / accent / success / warning /
                     danger), optional mono and leading icon.
- FaiStatusDot       breathing dot, used as a "live" indicator.
- FaiDataRow         Linear-style dense row for the audit
                     stream — hover-elevation, mono leading,
                     coloured leading stripe.
- FaiEmptyState      gracious icon + title + hint + action,
                     replaces "(no data)" everywhere.
- FaiDeltaMark       the ∆ signature element. Three modes —
                     idle (still), live (gentle pulse), busy
                     (slow rotation). Drawn from primitives,
                     not a font glyph. Lives in the sidebar
                     header so the brand is always visible.

Page-level changes:
- main.dart        custom 220px sidebar replaces the Material
                   NavigationRail. ∆ on top, hub-connection
                   pill below it, hover-animated destinations,
                   page transitions are 200ms slide+fade.
- modules.dart     FaiCard rows with capability pills.
- audit.dart       FaiDataRow stream, segmented filter chips,
                   live status bar with hash-chain badge.
- approvals.dart   FaiCard with accent-top stripe, structured
                   action footer, toast on approve/reject,
                   themed reject-reason dialog.

google_fonts added as dep. flutter analyze clean. flutter test
2/2. flutter build macos --debug succeeds.

Bumps fai_studio 0.2.0 -> 0.3.0.

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

lib/widgets/fai_pill.dart

@@ -0,0 +1,90 @@
+// FaiPill — small inline label. Used for capabilities, versions,
+// permission scopes, status text. Replaces ad-hoc Container chips.
+
+import 'package:flutter/material.dart';
+
+import '../theme/theme.dart';
+import '../theme/tokens.dart';
+
+enum FaiPillTone {
+  neutral,
+  accent,
+  success,
+  warning,
+  danger,
+}
+
+class FaiPill extends StatelessWidget {
+  final String label;
+  final FaiPillTone tone;
+  final IconData? icon;
+  final bool monospace;
+
+  const FaiPill({
+    super.key,
+    required this.label,
+    this.tone = FaiPillTone.neutral,
+    this.icon,
+    this.monospace = false,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+    final (bg, fg) = _colors(theme.colorScheme);
+    final textStyle = monospace
+        ? FaiTheme.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,
+      ),
+      decoration: BoxDecoration(
+        color: bg,
+        borderRadius: BorderRadius.circular(FaiRadius.sm),
+      ),
+      child: Row(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          if (icon != null) ...[
+            Icon(icon, size: 11, color: fg),
+            const SizedBox(width: 4),
+          ],
+          Text(label, style: textStyle),
+        ],
+      ),
+    );
+  }
+
+  (Color, Color) _colors(ColorScheme scheme) {
+    switch (tone) {
+      case FaiPillTone.neutral:
+        return (scheme.surfaceContainerHighest, scheme.onSurfaceVariant);
+      case FaiPillTone.accent:
+        return (
+          scheme.primary.withValues(alpha: 0.15),
+          scheme.primary,
+        );
+      case FaiPillTone.success:
+        return (
+          FaiColors.success.withValues(alpha: 0.15),
+          scheme.brightness == Brightness.dark
+              ? FaiColors.success
+              : const Color(0xFF15803D),
+        );
+      case FaiPillTone.warning:
+        return (
+          FaiColors.warning.withValues(alpha: 0.15),
+          scheme.brightness == Brightness.dark
+              ? FaiColors.warning
+              : const Color(0xFFB45309),
+        );
+      case FaiPillTone.danger:
+        return (
+          scheme.errorContainer,
+          scheme.onErrorContainer,
+        );
+    }
+  }
+}