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_status_dot.dart

@@ -0,0 +1,101 @@
+// FaiStatusDot — 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 {
+  final Color color;
+
+  /// When true, the dot fades between full and 30% opacity.
+  /// When false, it stays at full opacity (steady-state).
+  final bool pulsing;
+
+  final double size;
+
+  const FaiStatusDot({
+    super.key,
+    required this.color,
+    this.pulsing = false,
+    this.size = 8,
+  });
+
+  @override
+  State<FaiStatusDot> createState() => _FaiStatusDotState();
+}
+
+class _FaiStatusDotState extends State<FaiStatusDot>
+    with SingleTickerProviderStateMixin {
+  late final AnimationController _ctrl;
+
+  @override
+  void initState() {
+    super.initState();
+    _ctrl = AnimationController(
+      vsync: this,
+      duration: const Duration(milliseconds: 1400),
+    );
+    if (widget.pulsing) _ctrl.repeat(reverse: true);
+  }
+
+  @override
+  void didUpdateWidget(covariant FaiStatusDot old) {
+    super.didUpdateWidget(old);
+    if (widget.pulsing && !_ctrl.isAnimating) {
+      _ctrl.repeat(reverse: true);
+    } else if (!widget.pulsing && _ctrl.isAnimating) {
+      _ctrl.stop();
+      _ctrl.value = 0;
+    }
+  }
+
+  @override
+  void dispose() {
+    _ctrl.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return AnimatedBuilder(
+      animation: _ctrl,
+      builder: (_, _) {
+        final t = widget.pulsing ? _ctrl.value : 0.0;
+        final alpha = 1.0 - (t * 0.6);
+        return Container(
+          width: widget.size,
+          height: widget.size,
+          decoration: BoxDecoration(
+            color: widget.color.withValues(alpha: alpha),
+            shape: BoxShape.circle,
+            boxShadow: widget.pulsing
+                ? [
+                    BoxShadow(
+                      color: widget.color.withValues(alpha: 0.4 * alpha),
+                      blurRadius: 6 * (1 + t),
+                      spreadRadius: 1 * t,
+                    ),
+                  ]
+                : const [],
+          ),
+        );
+      },
+    );
+  }
+}
+
+/// Convenience presets.
+class FaiStatusDots {
+  FaiStatusDots._();
+  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,
+      );
+}