feat: add task retry functionality with UI feedback

Implement comprehensive task retry feature across backend and frontend:
- Add input validation and event emission for RetryTask method
- Add retry button with loading states for failed tasks
- Improve error display and user feedback during retry operations
- Set default window dimensions for consistent initial layout

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: STRRL

app.go

@@ -27,6 +27,11 @@ const (
 	ProgressTaskComplete       = 100
 )
 
+const (
+	defaultWindowWidth  = 3464
+	defaultWindowHeight = 2200
+)
+
 // App struct
 type App struct {
 	ctx           context.Context
@@ -81,6 +86,10 @@ func (a *App) startup(ctx context.Context) {
 	a.ctx = ctx
 	a.logger.Info("TransCube starting up")
 
+	if err := runtime.WindowSetSize(a.ctx, defaultWindowWidth, defaultWindowHeight); err != nil {
+		a.logger.Warn("Failed to set window size", "error", err)
+	}
+
 	// Log environment info for debugging
 	pathFinder := utils.NewPathFinder()
 	debugInfo := pathFinder.DebugInfo()
@@ -289,6 +298,14 @@ func (a *App) ensureTaskLoaded(taskID string) (*types.Task, error) {
 
 // RetryTask retries a failed task
 func (a *App) RetryTask(taskID string) (*types.Task, error) {
+	if taskID == "" {
+		return nil, fmt.Errorf("taskID is required")
+	}
+
+	if _, err := a.ensureTaskLoaded(taskID); err != nil {
+		return nil, err
+	}
+
 	task, err := a.taskManager.RetryTask(taskID)
 	if err != nil {
 		return nil, err
@@ -297,6 +314,7 @@ func (a *App) RetryTask(taskID string) (*types.Task, error) {
 	a.logger.Info("Retrying task", "taskId", taskID)
 
 	go a.processTask(taskID)
+	a.emitReloadEvent()
 
 	return task, nil
 }

frontend/src/pages/HomePage.tsx

@@ -15,7 +15,7 @@ import {
   AlertDialogTitle,
 } from '@/components/ui/alert-dialog'
 import { Clock, Plus, Trash2, RefreshCcw, Loader2 } from 'lucide-react'
-import { GetAllTasks, DeleteTask, ListActiveTasks } from '../../wailsjs/go/main/App'
+import { GetAllTasks, DeleteTask, ListActiveTasks, RetryTask } from '../../wailsjs/go/main/App'
 import { EventsOn } from '../../wailsjs/runtime/runtime'
 
 export default function HomePage() {
@@ -32,6 +32,7 @@ export default function HomePage() {
   const [refreshing, setRefreshing] = useState(false)
   const [pollMs, setPollMs] = useState(1500)
   const idleRoundsRef = useRef(0)
+  const [retryingTasks, setRetryingTasks] = useState<Record<string, boolean>>({})
 
   const isActiveStatus = useCallback(
     (status: string | undefined) =>
@@ -158,6 +159,23 @@ export default function HomePage() {
     }
   }
 
+  const handleRetry = useCallback(async (taskId: string) => {
+    setRetryingTasks((prev) => ({ ...prev, [taskId]: true }))
+    try {
+      await RetryTask(taskId)
+      await Promise.all([loadTasks(), loadActiveTasks()])
+    } catch (err) {
+      console.error('Retry failed:', err)
+      const message = err instanceof Error ? err.message : 'Failed to retry task'
+      alert(message)
+    } finally {
+      setRetryingTasks((prev) => {
+        const { [taskId]: _removed, ...rest } = prev
+        return rest
+      })
+    }
+  }, [loadActiveTasks, loadTasks])
+
   const combinedTasks = useMemo(() => {
     const tasks = [...activeTasks, ...processedVideos]
     return tasks.sort((a, b) => {
@@ -348,10 +366,31 @@ export default function HomePage() {
                     </p>
                   </div>
 
-                  {task.status === 'failed' && task.error && (
-                    <p className="text-xs text-destructive leading-relaxed">
-                      Error: {task.error}
-                    </p>
+                  {task.status === 'failed' && (
+                    <div className="space-y-2">
+                      {task.error && (
+                        <p className="text-xs text-destructive leading-relaxed">
+                          Error: {task.error}
+                        </p>
+                      )}
+                      <Button
+                        variant="outline"
+                        size="sm"
+                        className="w-fit"
+                        onClick={() => handleRetry(task.id)}
+                        disabled={!!retryingTasks[task.id]}
+                        type="button"
+                      >
+                        {retryingTasks[task.id] ? (
+                          <>
+                            <Loader2 className="h-4 w-4 mr-2 animate-spin" />
+                            Retrying…
+                          </>
+                        ) : (
+                          'Retry'
+                        )}
+                      </Button>
+                    </div>
                   )}
                 </CardContent>
               </Card>