Initial commit: RSS platform phase 1 skeleton with code review fixes

Features:
- FastAPI + SQLAlchemy 2.0 async + PostgreSQL/pgvector + Redis backend
- Vue 3 + TypeScript + Element Plus frontend
- JWT auth with access/refresh tokens and revocation
- Admin/member RBAC
- RSS feed CRUD and article listing
- Settings management with Fernet encryption for sensitive values
- Redis distributed lock service
- Alembic initial migration
- Docker Compose development environment

Fixes from code review:
- Fix DB session leak in dependency injection
- Restrict registration to admin only
- Add default admin password warning
- Implement JWT refresh tokens and jti blacklist
- Strengthen password policy
- Use func.count for pagination totals
- Replace NullPool with AsyncAdaptedQueuePool
- Remove init_db from lifespan to enforce alembic migrations
- Add request_id middleware and logging filter
- Fix vite.config.ts env loading
- Add frontend token refresh interceptor
- Add Vue error handler

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/alembic/script.py.mako

@@ -0,0 +1,26 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision: str = ${repr(up_revision)}
+down_revision: Union[str, None] = ${repr(down_revision)}
+branch_labels: Union[str, Sequence[str], None] = ${repr(branch_labels)}
+depends_on: Union[str, Sequence[str], None] = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}