Initial commit: Pixel AI comic/video creation platform

- FastAPI backend with SQLModel, Alembic migrations, AgentScope agents
- Next.js 15 frontend with React 19, Tailwind, Zustand, React Flow
- Multi-provider AI system (DashScope, Kling, MiniMax, Volcengine, OpenAI, etc.)
- All HTTP clients migrated from sync requests to async httpx
- Admin-managed API keys via environment variables
- SSRF vulnerability fixed in ensure_url()

frontend/src/components/canvas/controls/interaction-input/selectors/index.ts

@@ -0,0 +1,3 @@
+export { ModelSelector } from './ModelSelector';
+export { StyleSelector } from './StyleSelector';
+export { AssetSelector } from './AssetSelector';