animate the running turn indicator with rotating verbs (T-255)

The static gray `running…` gave no sense anything was happening. Replace it
with a RunningIndicator: an animated ellipsis (Pondering → . → .. → ...) and a
curated, on-brand verb that rotates every few seconds (Pondering, Conjuring,
Brewing, …).

The verbs are clide-owned, not the Claude Code CLI's — that list is a TUI
cosmetic the stream-json protocol doesn't surface, and reusing the bundled
strings is a licensing gray area, so a curated list keeps us self-contained
(own-the-rendering-stack, D-75). Animation is driven off a single
AnimationController's value (no timers) so tests advance it with bounded
pumps; reduced-motion shows a static verb and the a11y label stays stable.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/builtin/claude/src/claude_composer.dart

@@ -13,6 +13,7 @@ import 'dart:io';
 
 import 'package:clide/builtin/claude/src/claude_config.dart';
 import 'package:clide/builtin/claude/src/clipboard_paste.dart';
+import 'package:clide/builtin/claude/src/running_indicator.dart';
 import 'package:clide/builtin/claude/src/slash_commands.dart';
 import 'package:clide/kernel/src/theme/controller.dart';
 import 'package:clide/kernel/src/theme/tokens.dart';
@@ -483,7 +484,7 @@ class _ClaudeComposerState extends State<ClaudeComposer> {
                   padding: const EdgeInsets.only(bottom: 8),
                   child: Row(
                     children: [
-                      ClideText('running…', muted: true, fontSize: clideFontMeta),
+                      const RunningIndicator(),
                       const Spacer(),
                       ClideButton(
                         label: 'Stop  ⎋',

lib/builtin/claude/src/running_indicator.dart

@@ -0,0 +1,89 @@
+/// In-flight turn indicator (T-255): a muted, animated label shown next to the
+/// Stop button while a Claude turn runs. Animated ellipsis (`Pondering` →
+/// `Pondering.` → `..` → `...`) plus a verb that rotates every few seconds.
+///
+/// The verbs are clide-owned, NOT the Claude Code CLI's: that list is a TUI
+/// cosmetic the stream-json protocol doesn't expose, and reusing the bundled
+/// strings is a licensing gray area — a curated list keeps us self-contained
+/// (own-the-rendering-stack, D-75). Animation is driven off a single
+/// [AnimationController]'s value (no timers) so tests advance it with bounded
+/// pumps; reduced-motion shows a static verb and the a11y label stays stable.
+library;
+
+import 'package:clide/widgets/widgets.dart';
+import 'package:flutter/widgets.dart';
+
+/// Curated, on-brand present participles. Muted and tasteful — not the CLI's.
+const List<String> runningVerbs = [
+  'Pondering',
+  'Conjuring',
+  'Brewing',
+  'Tinkering',
+  'Noodling',
+  'Percolating',
+  'Computing',
+  'Wrangling',
+  'Untangling',
+  'Synthesizing',
+  'Cogitating',
+  'Whirring',
+];
+
+/// Seconds each verb is shown before rotating to the next.
+const int _secondsPerWord = 4;
+
+class RunningIndicator extends StatefulWidget {
+  const RunningIndicator({super.key});
+
+  @override
+  State<RunningIndicator> createState() => _RunningIndicatorState();
+}
+
+class _RunningIndicatorState extends State<RunningIndicator> with SingleTickerProviderStateMixin {
+  // One full pass over every verb; value 0→1 maps linearly to elapsed seconds.
+  static final int _periodSeconds = runningVerbs.length * _secondsPerWord;
+
+  late final AnimationController _c = AnimationController(
+    vsync: this,
+    duration: Duration(seconds: _periodSeconds),
+  );
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    final reduced = MediaQuery.maybeOf(context)?.disableAnimations ?? false;
+    if (reduced) {
+      if (_c.isAnimating) _c.stop();
+    } else if (!_c.isAnimating) {
+      _c.repeat();
+    }
+  }
+
+  @override
+  void dispose() {
+    _c.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final reduced = MediaQuery.maybeOf(context)?.disableAnimations ?? false;
+    // The animated text is decorative; AT gets one stable label.
+    return Semantics(
+      label: 'Claude is running',
+      child: ExcludeSemantics(
+        child: reduced
+            ? ClideText('${runningVerbs.first}…', muted: true, fontSize: clideFontMeta)
+            : AnimatedBuilder(
+                animation: _c,
+                builder: (ctx, _) {
+                  final elapsed = _c.value * _periodSeconds;
+                  final dots = '.' * (elapsed.floor() % 4);
+                  final word = runningVerbs[(elapsed ~/ _secondsPerWord) % runningVerbs.length];
+                  return ClideText('$word$dots', muted: true, fontSize: clideFontMeta);
+                },
+              ),
+      ),
+    );
+  }
+}