refactor(programmer): shared task card driven by run states

Extract _TaskCard from the list screen into ProgrammerTaskCard, a
shared ConsumerWidget that reads programmerRunStatesProvider so the
paused-task pill and Start/Resume/Complete buttons are consistent
across any surface that embeds it.

Move the _complete body verbatim to completeProgrammerTaskWithConfirm
in programmer_task_actions.dart; the detail screen's _ActionBar now
calls the shared function.

Co-Authored-By: claude-flow <ruv@ruv.net>

lib/screens/programmer_tasks/programmer_task_actions.dart

@@ -4,6 +4,40 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import '../../models/programmer_task.model.dart';
 import '../../providers/programmer_tasks_provider.dart';
 
+/// Confirms with the user and completes [task]. Body moved verbatim from the
+/// detail screen's `_complete` so it can be called from both the card and the
+/// detail action bar.
+Future<void> completeProgrammerTaskWithConfirm(
+  BuildContext context,
+  WidgetRef ref,
+  ProgrammerTask task,
+) async {
+  final messenger = ScaffoldMessenger.of(context);
+  final ok = await showDialog<bool>(
+    context: context,
+    builder: (context) => AlertDialog(
+      semanticLabel: 'Complete task',
+      title: const Text('Complete task?'),
+      content: Text('Mark "${task.title}" as completed?'),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.of(context).pop(false),
+          child: const Text('Cancel'),
+        ),
+        FilledButton(
+          onPressed: () => Navigator.of(context).pop(true),
+          child: const Text('Complete'),
+        ),
+      ],
+    ),
+  );
+  if (ok != true) return;
+  await ref
+      .read(programmerTasksControllerProvider)
+      .completeTask(taskId: task.id);
+  messenger.showSnackBar(const SnackBar(content: Text('Task completed')));
+}
+
 /// Starts (or resumes) [task] for the current user, enforcing the single-active
 /// task discipline: if the user already has a *running* task, they are prompted
 /// to pause it first. This is the headline "proper time management" behavior and