fix: auto-start agent after spec creation from empty Kanban

When creating a spec from an empty Kanban board (via "Create Spec" button),
the agent was not automatically starting after clicking "Continue to Project".

Root cause: The SpecCreationChat component in App.tsx had an onComplete handler
that only closed the chat and refreshed queries, but did not call startAgent().
This was different from the NewProjectModal flow which correctly started the agent.

Changes:
- Add startAgent import to App.tsx
- Update onComplete handler to call startAgent() with yoloMode and maxConcurrency

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ui/src/App.tsx

@@ -28,7 +28,7 @@ import { KeyboardShortcutsHelp } from './components/KeyboardShortcutsHelp'
 import { ThemeSelector } from './components/ThemeSelector'
 import { ResetProjectModal } from './components/ResetProjectModal'
 import { ProjectSetupRequired } from './components/ProjectSetupRequired'
-import { getDependencyGraph } from './lib/api'
+import { getDependencyGraph, startAgent } from './lib/api'
 import { Loader2, Settings, Moon, Sun, RotateCcw } from 'lucide-react'
 import type { Feature } from './lib/types'
 import { Button } from '@/components/ui/button'
@@ -495,7 +495,16 @@ function App() {
         <div className="fixed inset-0 z-50 bg-background">
           <SpecCreationChat
             projectName={selectedProject}
-            onComplete={() => {
+            onComplete={async (_specPath, yoloMode) => {
+              // Auto-start the agent after spec creation (same as NewProjectModal)
+              try {
+                await startAgent(selectedProject, {
+                  yoloMode: yoloMode ?? false,
+                  maxConcurrency: 3,
+                })
+              } catch (err) {
+                console.error('Failed to start agent:', err)
+              }
               setShowSpecChat(false)
               // Refresh projects to update has_spec
               queryClient.invalidateQueries({ queryKey: ['projects'] })