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/alembic/versions/0002_add_api_key_to_providers.py

@@ -0,0 +1,29 @@
+"""add api_key to providers
+
+Revision ID: 0002_add_api_key_to_providers
+Revises: 0001_init_providers_and_story_mode
+Create Date: 2025-01-01
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "0002_add_api_key"
+down_revision = "0001_init_providers"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # 添加 api_key 列，可为空，优先于 config_ref 使用
+    with op.batch_alter_table("providers", schema=None) as batch_op:
+        batch_op.add_column(
+            sa.Column("api_key", sa.String(length=500), nullable=True)
+        )
+
+
+def downgrade() -> None:
+    with op.batch_alter_table("providers", schema=None) as batch_op:
+        batch_op.drop_column("api_key")