UI-03: shared floating-glass component kit

Adds GlassPanel (BackdropFilter + translucent fill + subtle border, values
lifted directly from the Stitch exports' own bg-surface/90 backdrop-blur-xl
border-outline-variant/30 treatment), FloatingPill (a GlassPanel shaped as
a capsule around an arbitrary number of labeled stat columns with
dividers), and PulsingLocationMarker (expanding-ring-plus-glow-dot,
matching the exports' pulse-ring keyframes exactly, with a static-dot
fallback when reduced motion is requested). Pure presentation -- every
UI-04/05/06/07 screen composes these rather than reimplementing blur/
border styling per screen.

Adds outlineVariant to ripprColors, needed for the panel border and pill
dividers and not previously wired up by UI-08.

Verified with a throwaway preview entry point (deleted after use, no
consuming screen exists yet) plus 8 new widget tests covering blur/
translucency/border structure, contrast in both themes, arbitrary stat
counts, and the pulsing marker's animation lifecycle and reduced-motion
fallback.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012Xki7YAcc2TiN2PRZJ2tXr

lib/src/ui/components/pulsing_location_marker.dart

@@ -0,0 +1,109 @@
+/// UI-03: the expanding-ring-plus-glow-dot user-location marker from the Plan/Route
+/// Planning exports. Values (sizes, colours, the scale/opacity curve) are lifted from
+/// the exports' own `pulse-ring` keyframes, not guessed -- see
+/// `docs/design/stitch-export/screens/route-planning-dark.html`.
+library;
+
+import 'package:flutter/material.dart';
+
+class PulsingLocationMarker extends StatefulWidget {
+  const PulsingLocationMarker({super.key});
+
+  @override
+  State<PulsingLocationMarker> createState() => _PulsingLocationMarkerState();
+}
+
+class _PulsingLocationMarkerState extends State<PulsingLocationMarker>
+    with SingleTickerProviderStateMixin {
+  late final _controller = AnimationController(
+    vsync: this,
+    duration: const Duration(seconds: 2),
+  );
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    _syncWithReducedMotion();
+  }
+
+  /// A static dot -- the ring never expands -- when the platform has reduced motion
+  /// enabled, the same accessibility setting `prefers-reduced-motion` maps to on the
+  /// web this component's design came from.
+  void _syncWithReducedMotion() {
+    final reduceMotion = MediaQuery.maybeOf(context)?.disableAnimations ?? false;
+    if (reduceMotion) {
+      _controller.stop();
+    } else if (!_controller.isAnimating) {
+      _controller.repeat();
+    }
+  }
+
+  @override
+  void dispose() {
+    _controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final colors = Theme.of(context).colorScheme;
+    return SizedBox(
+      width: 40,
+      height: 40,
+      child: AnimatedBuilder(
+        animation: _controller,
+        builder: (context, child) {
+          // The keyframes' own 0%/70%/100% easing: scale 0.8 -> 1.0 and opacity
+          // 0.8 -> 0, both eased out rather than linear, so the ring visibly slows as
+          // it fades rather than looking like it's cut off mid-motion.
+          final t = Curves.easeOut.transform(_controller.value);
+          final scale = 0.8 + (0.2 * t);
+          final opacity = 0.8 * (1 - t);
+          return Stack(
+            alignment: Alignment.center,
+            children: [
+              // The faint, static outer ring -- always present, pulse or no pulse.
+              Container(
+                width: 16,
+                height: 16,
+                decoration: BoxDecoration(
+                  color: colors.primary.withValues(alpha: 0.3),
+                  shape: BoxShape.circle,
+                ),
+              ),
+              Transform.scale(
+                scale: scale,
+                child: Opacity(
+                  opacity: opacity,
+                  child: Container(
+                    width: 12,
+                    height: 12,
+                    decoration: BoxDecoration(
+                      color: colors.primary,
+                      shape: BoxShape.circle,
+                    ),
+                  ),
+                ),
+              ),
+              Container(
+                width: 8,
+                height: 8,
+                decoration: BoxDecoration(
+                  color: colors.primary,
+                  shape: BoxShape.circle,
+                  boxShadow: [
+                    BoxShadow(
+                      color: colors.primary.withValues(alpha: 0.5),
+                      blurRadius: 10,
+                      spreadRadius: 1,
+                    ),
+                  ],
+                ),
+              ),
+            ],
+          );
+        },
+      ),
+    );
+  }
+}