Initial commit: clean project structure

- Backend: FastAPI + SQLAlchemy + Celery (Python 3.11+)
- Frontend: Vue 3 + TypeScript + Pinia + Tailwind
- Admin Frontend: separate Vue 3 app for management
- Docker Compose: 9 services orchestration
- Specs: design prototypes, memory system PRD, product roadmap

Cleanup performed:
- Removed temporary debug scripts from backend root
- Removed deprecated admin_app.py (embedded UI)
- Removed duplicate docs from admin-frontend
- Updated .gitignore for Vite cache and egg-info

backend/app/core/deps.py

@@ -0,0 +1,39 @@
+from fastapi import Cookie, Depends, HTTPException, status
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.security import decode_access_token
+from app.db.database import get_db
+from app.db.models import User
+
+
+async def get_current_user(
+    access_token: str | None = Cookie(default=None),
+    db: AsyncSession = Depends(get_db),
+) -> User | None:
+    """获取当前用户（可选）。"""
+    if not access_token:
+        return None
+
+    payload = decode_access_token(access_token)
+    if not payload:
+        return None
+
+    user_id = payload.get("sub")
+    if not user_id:
+        return None
+
+    result = await db.execute(select(User).where(User.id == user_id))
+    return result.scalar_one_or_none()
+
+
+async def require_user(
+    user: User | None = Depends(get_current_user),
+) -> User:
+    """要求用户登录，否则抛 401。"""
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="未登录",
+        )
+    return user