feat: initial MVP - FastAPI backend + Vue3 frontend + docker-compose

- backend: FastAPI + SQLAlchemy 2.0(async) + asyncpg + Alembic
- 7 API routes: auth/me/articles/sources/bookmarks/subscriptions/admin
- models: User/Source/Article/Bookmark/Subscription/ApiToken
- services: RSS fetcher (feedparser) + Tencent TMT translator with quota + cache + local NLLB fallback
- workers: APScheduler + asyncio pipeline (fetch -> dedupe -> insert -> translate)
- seed scripts: create_user, seed_sources (5 RSS: Reuters/BBC/Al Jazeera/NHK/DW)
- frontend: Vue 3 + Vite + Naive UI + Pinia + vue-router
- pages: Login, Feed (24h), ArticleDetail, Sources, Bookmarks, AdminSources
- deploy: docker-compose (postgres/redis/api/worker/frontend/caddy)
- docs: README, DEPLOY, architecture, acceptance

backend/alembic/env.py

@@ -0,0 +1,59 @@
+"""Alembic 环境配置:从 app.config 读取 URL,启用 autogenerate。"""
+from __future__ import annotations
+
+import sys
+from logging.config import fileConfig
+from pathlib import Path
+
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+
+# 让 alembic 能 import app
+sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
+
+from app.config import settings  # noqa: E402
+from app.database import Base  # noqa: E402
+from app.models import *  # noqa: F401, F403, E402
+
+config = context.config
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+config.set_main_option("sqlalchemy.url", settings.sync_database_url)
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+        compare_type=True,
+    )
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+    with connectable.connect() as connection:
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            compare_type=True,
+        )
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()