chore(async-infra): 异步基础层 + 工具链 + 清理

异步基础层（core/）：
- db.py   aiosqlite + WAL：读路径无锁并发、写路径 asyncio.Lock 串行，
          busy_timeout 自旋——实现「读写同时进行」（旧实现用 RLock 全读串行）
- http_client.py  aiohttp 连接池 + 有界重试（5xx 重试 / 4xx 不重试）+
          响应体上限 + 流式接口；按事件循环隔离 session（支持迁移期双 loop）

工具链：
- pyproject.toml   ruff(E/F/W/I/B/UP/C4/ASYNC/S/RUF) + pyright(basic) + pytest(asyncio auto)
- requirements-fastapi.txt  FastAPI/aiohttp/aiosqlite/aiofiles 等目标栈
- requirements-dev.txt      开发依赖（pytest/ruff/pyright）

清理：删除无用脚本 _csscheck.py 与产物标记 _css_ok.txt/_pkg_ok.txt，同步 .gitignore

验证：pytest 10/10（含「写 200 条同时 4 读协程零异常」并发用例）；
ruff All checks passed；pyright 0 errors。

_csscheck.py

@@ -1,10 +0,0 @@
-# -*- coding: utf-8 -*-
-"""CSS 完整性检查：花括号平衡 + 关键美化标记存活"""
-import sys
-src = open('templates/index.html', encoding='utf-8').read()
-style = src.split('<style>')[1].split('</style>')[0]
-ok = style.count('{') == style.count('}')
-marks = sum(1 for m in ['font-family: inherit', 'kw.on { text-shadow', 'uc-card:hover', 'theme-fading', 'textarea.input', 'prefers-reduced-motion', '美化层 v4', '美化层 v5', 'safe-area-inset'] if m in style)
-with open('_css_ok.txt', 'w', encoding='utf-8') as f:
-    f.write(f'braces={style.count("{")}=={style.count("}")} {ok} | marks {marks}/9')
-print('ok')

core/config.py

@@ -4,10 +4,10 @@
 自 main.py 原样迁出，语义不变：仅常量、配置类与路径定义。
 不导入 flask/fastapi，不持有任何运行时可变状态（运行时状态见 core.state）。
 """
+
 import os
 from dataclasses import dataclass
 
-
 # 站点统一版本号（P3-12/P3-22：/health、/api/info、前端 CHANGELOG 全部以此为准，别处不得硬编码）
 APP_VERSION = '2.4.0'
 
@@ -19,6 +19,7 @@ RESULT_RETENTION_SECONDS = 35 * 60
 @dataclass
 class Settings:
     """服务配置类（原 main.APIConfig；迁移期保留 APIConfig 别名以兼容既有引用）"""
+
     host: str = '0.0.0.0'
     port: int = 5000
     debug: bool = False
@@ -26,7 +27,9 @@ class Settings:
     # 第 98 条：max_file_size/request_timeout 两个架空字段已删除——请求体上限真实
     # 生效点是 _body_size_limit（业务 2MB/备份 200MB），上游超时在 music_api 各调用点
     log_level: str = 'INFO'
-    cors_origins: str = (os.environ.get('CORS_ORIGINS') or '*').strip() or '*'   # 第 100 条：可经环境变量收敛同源（空值回落默认）
+    cors_origins: str = (
+        os.environ.get('CORS_ORIGINS') or '*'
+    ).strip() or '*'  # 第 100 条：可经环境变量收敛同源（空值回落默认）
 
 
 # 向后兼容别名：既有代码/文档沿用 APIConfig 名称
@@ -57,7 +60,7 @@ BATCH_ZIP_CONCURRENCY = 3
 
 
 # 音频直链多重防护（HMAC 签名 + 时效 + 代理流）
-AUDIO_TOKEN_TTL = RESULT_RETENTION_SECONDS + 60   # 第 93 条（P2-4）：= 36 分钟——原 30 分钟
+AUDIO_TOKEN_TTL = RESULT_RETENTION_SECONDS + 60  # 第 93 条（P2-4）：= 36 分钟——原 30 分钟
 # 大于交付/解析结果 35 分钟保留期 60 秒：交付窗口末段试听不再 403（旧 30 分钟口径矛盾已修）
 AUDIO_URL_KEYS = {'url', 'audioUrl'}
 AUDIO_HOST_MARKS = ('126.net', 'music.126.net', '.netease')

core/db.py

@@ -0,0 +1,137 @@
+# -*- coding: utf-8 -*-
+"""异步 SQLite 访问层（aiosqlite + WAL）。
+
+核心目标：**读写同时进行**。
+- WAL 模式：读事务与写事务互不阻塞（读快照隔离），这是 SQLite 层并发的根本；
+- 读路径：每次操作独立连接、无锁、可并发（`fetch_all`/`fetch_one`/`fetch_val`）；
+- 写路径：SQLite 全库同一时刻只允许一个写者，用 `asyncio.Lock` 串行化写事务，
+  但写者不阻塞读者（WAL）；
+- `busy_timeout`：多进程/多连接下遇到短暂写锁自旋等待而非立刻 SQLITE_BUSY。
+
+与旧实现的差异：旧 `auth_system` 用 `threading.RLock` 把**全部**读写串行化，
+读也被写挡住；本层只串行化写，读放行并发，即「读写同时进行」。
+"""
+
+import asyncio
+import os
+from collections.abc import AsyncIterator, Iterable, Sequence
+from contextlib import asynccontextmanager
+from pathlib import Path
+from typing import Any
+
+import aiosqlite
+
+# 站点数据目录（可经环境变量覆盖，便于测试隔离）
+DATA_DIR = Path(os.environ.get('SITE_DATA_DIR', 'data'))
+DB_PATH = DATA_DIR / 'site.db'
+
+# 写事务串行锁（惰性创建，避免跨事件循环绑定）
+_WRITE_LOCK: asyncio.Lock | None = None
+
+
+def _write_lock() -> asyncio.Lock:
+    global _WRITE_LOCK
+    if _WRITE_LOCK is None:
+        _WRITE_LOCK = asyncio.Lock()
+    return _WRITE_LOCK
+
+
+async def _configure(conn: aiosqlite.Connection) -> None:
+    conn.row_factory = aiosqlite.Row
+    await conn.execute('PRAGMA journal_mode=WAL')  # 读写并发的前提
+    await conn.execute('PRAGMA busy_timeout=15000')  # 遇写锁自旋等待，而非立即报错
+    await conn.execute('PRAGMA synchronous=NORMAL')  # WAL 下兼顾安全与吞吐
+    await conn.execute('PRAGMA foreign_keys=ON')
+
+
+async def connect() -> aiosqlite.Connection:
+    """新建一个已配置好的连接（调用方负责 close）。"""
+    DATA_DIR.mkdir(parents=True, exist_ok=True)  # noqa: ASYNC240 - 幂等的微秒级一次目录创建，无需线程池
+    conn = await aiosqlite.connect(str(DB_PATH), timeout=15)
+    await _configure(conn)
+    return conn
+
+
+# ============ 读路径（并发，无锁） ============
+
+
+async def fetch_all(sql: str, params: Sequence = ()) -> list[aiosqlite.Row]:
+    conn = await connect()
+    try:
+        cur = await conn.execute(sql, params)
+        return list(await cur.fetchall())
+    finally:
+        await conn.close()
+
+
+async def fetch_one(sql: str, params: Sequence = ()) -> aiosqlite.Row | None:
+    conn = await connect()
+    try:
+        cur = await conn.execute(sql, params)
+        return await cur.fetchone()
+    finally:
+        await conn.close()
+
+
+async def fetch_val(sql: str, params: Sequence = (), default: Any = None) -> Any:
+    row = await fetch_one(sql, params)
+    return row[0] if row is not None else default
+
+
+# ============ 写路径（串行，不阻塞读） ============
+
+
+async def execute(sql: str, params: Sequence = ()) -> int:
+    """执行单条写语句，返回 lastrowid（INSERT）或 rowcount（UPDATE/DELETE）。"""
+    async with _write_lock():
+        conn = await connect()
+        try:
+            cur = await conn.execute(sql, params)
+            await conn.commit()
+            return cur.lastrowid if cur.lastrowid else cur.rowcount
+        finally:
+            await conn.close()
+
+
+async def execute_many(sql: str, seq: Iterable[Sequence]) -> int:
+    """批量写，返回受影响行数。"""
+    async with _write_lock():
+        conn = await connect()
+        try:
+            cur = await conn.executemany(sql, seq)
+            await conn.commit()
+            return cur.rowcount
+        finally:
+            await conn.close()
+
+
+@asynccontextmanager
+async def write_transaction() -> AsyncIterator[aiosqlite.Connection]:
+    """写事务上下文：多条写语句原子提交（串行锁内）。
+
+    用法：
+        async with write_transaction() as conn:
+            await conn.execute(...)
+            await conn.execute(...)
+        # 退出即 commit；异常则 rollback
+    """
+    async with _write_lock():
+        conn = await connect()
+        try:
+            yield conn
+            await conn.commit()
+        except Exception:
+            await conn.rollback()
+            raise
+        finally:
+            await conn.close()
+
+
+@asynccontextmanager
+async def read_connection() -> AsyncIterator[aiosqlite.Connection]:
+    """只读连接上下文（无锁、可并发）；需要在一个连接上做多次读时使用。"""
+    conn = await connect()
+    try:
+        yield conn
+    finally:
+        await conn.close()

core/http_client.py

@@ -0,0 +1,259 @@
+# -*- coding: utf-8 -*-
+"""异步 HTTP 客户端（aiohttp）：连接池 + 有界重试 + 响应体上限。
+
+替代旧的长连接 `requests.Session`/裸 `requests.get/post`：
+- 单一 `ClientSession` 复用 TCP 连接（keep-alive），连接池限制防上游打爆；
+- 重试口径与旧实现一致：网络异常/5xx 退避重试一次，4xx（429/460 风控）**不**重试；
+- 响应体超过 `max_bytes` 直接拒绝（防止被劫持/异常上游的超大 body 进内存）。
+
+异常层次（调用方按需映射为业务异常，例如 music_api.APIException）：
+    UpstreamError
+      ├── UpstreamNetworkError  网络/超时（可重试）
+      ├── UpstreamHTTPError     非 2xx（5xx 可重试，4xx 不可）
+      └── UpstreamTooLarge      响应体超限
+"""
+
+import asyncio
+import json
+from collections.abc import AsyncIterator, Mapping
+from contextlib import asynccontextmanager
+from dataclasses import dataclass, field
+from typing import Any
+
+import aiohttp
+
+DEFAULT_TIMEOUT = 30
+DEFAULT_MAX_BYTES = 8 * 1024 * 1024
+
+# 第 95 条（P2-6）/第 98 条口径：UA 与 Referer 由调用方传入（music_api.APIConstants）
+_EMPTY: Mapping[str, str] = {}
+
+
+class UpstreamError(Exception):
+    """上游请求错误基类。"""
+
+
+class UpstreamNetworkError(UpstreamError):
+    """网络异常/超时（可重试）。"""
+
+
+class UpstreamHTTPError(UpstreamError):
+    """上游返回非 2xx 状态码。"""
+
+    def __init__(self, status: int, message: str = ''):
+        super().__init__(f"HTTP {status} {message}".strip())
+        self.status = status
+
+
+class UpstreamTooLarge(UpstreamError):
+    """响应体超过大小上限。"""
+
+
+@dataclass
+class HTTPResult:
+    """一次请求的完整结果（供需要状态码/头/cookie 的调用点使用）。"""
+
+    status: int
+    url: str
+    text: str
+    headers: Mapping[str, str] = field(default_factory=dict)
+    cookies: Mapping[str, str] = field(default_factory=dict)
+
+    def json(self) -> Any:
+        return json.loads(self.text)
+
+
+class AsyncHTTPClient:
+    """带连接池的异步 HTTP 客户端。"""
+
+    def __init__(
+        self,
+        *,
+        total_timeout: float = DEFAULT_TIMEOUT,
+        max_bytes: int = DEFAULT_MAX_BYTES,
+        pool_limit: int = 100,
+        pool_per_host: int = 32,
+        user_agent: str | None = None,
+        referer: str | None = None,
+    ):
+        self._total_timeout = total_timeout
+        self._max_bytes = max_bytes
+        self._pool_limit = pool_limit
+        self._pool_per_host = pool_per_host
+        self._default_headers: dict[str, str] = {}
+        if user_agent:
+            self._default_headers['User-Agent'] = user_agent
+        if referer:
+            self._default_headers['Referer'] = referer
+        self._session: aiohttp.ClientSession | None = None
+        self._loop_sessions: dict[int, aiohttp.ClientSession] = {}
+        self._lock = asyncio.Lock()
+
+    async def _session_get(self) -> aiohttp.ClientSession:
+        if self._session is not None and not self._session.closed:
+            return self._session
+        async with self._lock:
+            if self._session is None or self._session.closed:
+                connector = aiohttp.TCPConnector(
+                    limit=self._pool_limit,
+                    limit_per_host=self._pool_per_host,
+                    ttl_dns_cache=300,
+                )
+                self._session = aiohttp.ClientSession(
+                    connector=connector,
+                    timeout=aiohttp.ClientTimeout(total=self._total_timeout),
+                    headers=dict(self._default_headers),
+                )
+        return self._session
+
+    async def _session_for_loop(self) -> aiohttp.ClientSession:
+        """按事件循环隔离 session。
+
+        迁移期同一进程内可能有两个 loop（FastAPI 主 loop + 遗留 Flask 的同步桥 loop）。
+        aiohttp 的 ClientSession 不能跨 loop 复用，故按 loop 分别持有。
+        """
+        key = id(asyncio.get_running_loop())
+        sess = self._loop_sessions.get(key)
+        if sess is not None and not sess.closed:
+            return sess
+        async with self._lock:
+            sess = self._loop_sessions.get(key)
+            if sess is None or sess.closed:
+                connector = aiohttp.TCPConnector(
+                    limit=self._pool_limit,
+                    limit_per_host=self._pool_per_host,
+                    ttl_dns_cache=300,
+                )
+                sess = aiohttp.ClientSession(
+                    connector=connector,
+                    timeout=aiohttp.ClientTimeout(total=self._total_timeout),
+                    headers=dict(self._default_headers),
+                )
+                self._loop_sessions[key] = sess
+        return sess
+
+    async def close(self) -> None:
+        if self._session is not None and not self._session.closed:
+            await self._session.close()
+        self._session = None
+        for sess in self._loop_sessions.values():
+            if not sess.closed:
+                await sess.close()
+        self._loop_sessions.clear()
+
+    # ---------- 底层：单次请求（不重试） ----------
+
+    async def _once(
+        self,
+        method: str,
+        url: str,
+        *,
+        headers: Mapping[str, str] | None = None,
+        cookies: Mapping[str, str] | None = None,
+        params: Mapping[str, Any] | None = None,
+        data: Any = None,
+        json_body: Any = None,
+        timeout: float | None = None,
+        allow_redirects: bool = True,
+    ) -> HTTPResult:
+        session = await self._session_for_loop()
+        req_timeout = aiohttp.ClientTimeout(total=timeout) if timeout else None
+        try:
+            async with session.request(
+                method,
+                url,
+                headers=dict(headers) if headers else None,
+                cookies=dict(cookies) if cookies else None,
+                params=params,
+                data=data,
+                json=json_body,
+                timeout=req_timeout,
+                allow_redirects=allow_redirects,
+            ) as resp:
+                body = await resp.read()
+                if len(body) > self._max_bytes:
+                    raise UpstreamTooLarge(f"上游响应体超过上限 {self._max_bytes} 字节")
+                if resp.status >= 400:
+                    raise UpstreamHTTPError(resp.status, resp.reason or '')
+                return HTTPResult(
+                    status=resp.status,
+                    url=str(resp.url),
+                    text=body.decode(resp.charset or 'utf-8', errors='replace'),
+                    headers=dict(resp.headers),
+                    cookies={k: v.value for k, v in resp.cookies.items()},
+                )
+        except aiohttp.ClientError as e:
+            raise UpstreamNetworkError(str(e)) from e
+        except TimeoutError as e:
+            raise UpstreamNetworkError('请求超时') from e
+
+    async def _with_retry(self, fn, *, attempts: int = 2, backoff: float = 1.0) -> HTTPResult:
+        """网络异常/5xx 退避重试；4xx 与超限立即抛出不重试。"""
+        last: UpstreamError | None = None
+        for i in range(attempts):
+            try:
+                return await fn()
+            except UpstreamHTTPError as e:
+                if e.status >= 500 and i + 1 < attempts:
+                    last = e
+                    await asyncio.sleep(backoff)
+                    continue
+                raise
+            except UpstreamNetworkError as e:
+                last = e
+                if i + 1 < attempts:
+                    await asyncio.sleep(backoff)
+                    continue
+                raise
+        # 理论上不可达
+        raise last or UpstreamError('上游请求失败')
+
+    # ---------- 高层 API ----------
+
+    async def request(self, method: str, url: str, **kw) -> HTTPResult:
+        return await self._with_retry(lambda: self._once(method, url, **kw))
+
+    async def get_text(self, url: str, **kw) -> str:
+        return (await self.request('GET', url, **kw)).text
+
+    async def post_text(self, url: str, **kw) -> str:
+        return (await self.request('POST', url, **kw)).text
+
+    async def get_json(self, url: str, **kw) -> Any:
+        return (await self.request('GET', url, **kw)).json()
+
+    async def post_json(self, url: str, **kw) -> Any:
+        return (await self.request('POST', url, **kw)).json()
+
+    @asynccontextmanager
+    async def stream(
+        self,
+        method: str,
+        url: str,
+        *,
+        headers: Mapping[str, str] | None = None,
+        cookies: Mapping[str, str] | None = None,
+        timeout: float | None = None,
+        allow_redirects: bool = True,
+    ) -> AsyncIterator[aiohttp.ClientResponse]:
+        """流式请求（下载/音视频代理用）：yield 原始响应，边读边写不整段入内存。"""
+        session = await self._session_for_loop()
+        req_timeout = aiohttp.ClientTimeout(total=timeout) if timeout else None
+        try:
+            async with session.request(
+                method,
+                url,
+                headers=dict(headers) if headers else None,
+                cookies=dict(cookies) if cookies else None,
+                timeout=req_timeout,
+                allow_redirects=allow_redirects,
+            ) as resp:
+                if resp.status >= 400:
+                    raise UpstreamHTTPError(resp.status, resp.reason or '')
+                yield resp
+        except aiohttp.ClientError as e:
+            raise UpstreamNetworkError(str(e)) from e
+
+
+# 进程级共享客户端（UA/Referer 由 music_api 在初始化后注入）
+client = AsyncHTTPClient()

core/security.py

@@ -5,16 +5,16 @@
 改为**启动时注入**（`init_secret_key`），从而解除对本模块对 Flask app 的依赖；
 签名/校验算法与口径保持逐字一致，迁移期新旧应用共用同一密钥即可互认 token。
 """
+
 import base64
 import hashlib
 import hmac
 import secrets
 import time
-from typing import Any, Optional
+from typing import Any
 
 from core.config import AUDIO_HOST_MARKS, AUDIO_TOKEN_TTL, AUDIO_URL_KEYS
 
-
 # 由应用启动时注入（来源：auth_system.get_secret_key() → app.secret_key）
 _SECRET_KEY: bytes = b''
 
@@ -36,11 +36,11 @@ def sign_payload(payload: str) -> str:
 def make_audio_token(url: str) -> str:
     exp = int(time.time()) + AUDIO_TOKEN_TTL
     nonce = secrets.token_hex(4)
-    payload = base64.urlsafe_b64encode(f'{exp}|{nonce}|{url}'.encode('utf-8')).decode().rstrip('=')
+    payload = base64.urlsafe_b64encode(f'{exp}|{nonce}|{url}'.encode()).decode().rstrip('=')
     return payload + '.' + sign_payload(payload)
 
 
-def verify_audio_token(token: str) -> Optional[str]:
+def verify_audio_token(token: str) -> str | None:
     try:
         payload, sig = token.rsplit('.', 1)
         if not hmac.compare_digest(sig, sign_payload(payload)):

core/state.py

@@ -12,14 +12,14 @@ Flask/FastAPI 迁移期共用，并为后续封装成带锁的单例（State 对
 依赖仅限标准库 threading/collections——任何下载器/HTTP 相关对象
 （如批量打包信号量）不放在这里，随对应服务模块搬迁。
 """
+
 import collections
 import threading
-from typing import Any, Dict, List
+from typing import Any
-
 
 # ============ 短链展开结果缓存 ============
 # 用户反复解析同一分享链接不再重复请求 163cn.tv（有界防膨胀）
-SHORTLINK_CACHE: Dict[str, str] = {}
+SHORTLINK_CACHE: dict[str, str] = {}
 SHORTLINK_CACHE_LOCK = threading.Lock()
 
 
@@ -37,23 +37,23 @@ BATCH_DURATIONS_LOCK = threading.Lock()
 # ============ 下载任务表 ============
 # （批量打包 + 单曲下载统一）：task_id -> {type, total, done, failed, status, start, msg, cancel, pause, device_id, result, params}
 # 前端通过 /api/batch_progress 轮询进度，支持取消；完成后文件按 35 分钟保留期清理
-DOWNLOAD_TASKS: Dict[str, Dict[str, Any]] = {}
+DOWNLOAD_TASKS: dict[str, dict[str, Any]] = {}
 DOWNLOAD_TASKS_LOCK = threading.Lock()
 
 
 # ============ 设备在线心跳 ============
 # device_id -> 最近心跳时间。心跳超时（PAUSE_AFTER_SECONDS）未上线的设备，其批量任务
 # 自动暂停让出排队名额；超时超过 CANCEL_AFTER_SECONDS（30 分钟）则自动取消任务并删文件
-DEVICE_LAST_SEEN: Dict[str, float] = {}
+DEVICE_LAST_SEEN: dict[str, float] = {}
 DEVICE_LAST_SEEN_LOCK = threading.Lock()
 
 
 # ============ 接口请求统计 ============
-REQUEST_STATS: Dict[str, Dict[str, Any]] = {}
+REQUEST_STATS: dict[str, dict[str, Any]] = {}
 STATS_LOCK = threading.Lock()
 
 # 用户解析/下载操作记录（IP）；仅保留最近 2000 条
-REQ_LOG: List[Dict[str, Any]] = []
+REQ_LOG: list[dict[str, Any]] = []
 
 
 # ============ 上游探测缓存 ============
@@ -62,10 +62,10 @@ GLOBAL_MUSIC_U_CACHE = {'v': None, 'ts': 0.0}
 
 # 服务器网易云账号昵称缓存（10 分钟）：非管理员可见响应中遮蔽真实昵称
 SERVER_NICK_CACHE = {'nick': None, 'ts': 0.0}
-SERVER_NICK_LOCK = threading.Lock()   # 第 91 条（P3-9）：刷新单飞锁，防并发重复打上游
+SERVER_NICK_LOCK = threading.Lock()  # 第 91 条（P3-9）：刷新单飞锁，防并发重复打上游
-VIP_PROBE_LOCK = threading.Lock()     # 第 100 条：音质探测单飞锁（有界等待）
+VIP_PROBE_LOCK = threading.Lock()  # 第 100 条：音质探测单飞锁（有界等待）
 
 # 全局账号 VIP 探测缓存（5 分钟）：probe 一次要打 8 次网易云接口，
 # 公网下账号栏高频刷新会连累服务器账号触发风控。
 VIP_CACHE = {'data': None, 'ts': 0.0}
-VIP_USER_CACHE = {}   # user 路径按 cookie 哈希的 5 分钟缓存
+VIP_USER_CACHE = {}  # user 路径按 cookie 哈希的 5 分钟缓存

core/utils.py

@@ -4,10 +4,10 @@
 自 main.py 原样迁出：安全整数解析、控制台输出兜底、SRT 时间轴、
 LRC→SRT 转换、字段参数解析、163cn.tv 短链展开（含私有缓存）。
 """
+
 import re
 import sys
 import threading
-from typing import Any, Dict, List, Optional
 
 
 def safe_int(value, default: int) -> int:
@@ -34,7 +34,7 @@ def srt_time(t: float) -> str:
     h = int(t // 3600)
     m = int((t % 3600) // 60)
     s = int(t % 60)
-    ms = int(round((t - int(t)) * 1000))
+    ms = round((t - int(t)) * 1000)
     if ms >= 1000:
         ms = 999
     return f"{h:02d}:{m:02d}:{s:02d},{ms:03d}"
@@ -73,14 +73,14 @@ def format_lyric(lrc: str, lyric_format: str) -> str:
     for i, (t, text) in enumerate(timed):
         end = timed[i + 1][0] if i + 1 < len(timed) else t + 5
         if end <= t:
-            end = t + 1   # 同时间多行：给 1 秒最小区间，不再生成倒挂区间
+            end = t + 1  # 同时间多行：给 1 秒最小区间，不再生成倒挂区间
         out.append(f"{i + 1}\n{srt_time(t)} --> {srt_time(end)}\n{text}\n")
     if untimed:
         out.append('\n'.join(untimed))
     return '\n'.join(out)
 
 
-def parse_meta_fields(raw) -> Optional[List[str]]:
+def parse_meta_fields(raw) -> list[str] | None:
     """解析写入字段参数，空返回 None（表示全部写入）"""
     if raw is None or raw == '':
         return None
@@ -93,7 +93,7 @@ def parse_meta_fields(raw) -> Optional[List[str]]:
 
 
 # 短链展开结果缓存：用户反复解析同一分享链接不再重复请求 163cn.tv（有界防膨胀）
-_SHORTLINK_CACHE: Dict[str, str] = {}
+_SHORTLINK_CACHE: dict[str, str] = {}
 _SHORTLINK_CACHE_LOCK = threading.Lock()
 
 
@@ -106,6 +106,7 @@ def expand_shortlink(url: str) -> str:
     expanded = url
     try:
         import requests
+
         response = requests.get(url, allow_redirects=False, timeout=10)
         expanded = response.headers.get('Location', url)
     except Exception:

pyproject.toml

@@ -0,0 +1,63 @@
+# -*- coding: utf-8 -*-
+[project]
+name = "yunmusic-assistant"
+version = "3.0.0"
+description = "云村小助手 · 网易云音乐解析/下载服务（FastAPI + asyncio + aiohttp）"
+requires-python = ">=3.12"
+
+# ============ Ruff：静态检查 + 导入排序 + 格式化 ============
+[tool.ruff]
+target-version = "py312"
+line-length = 120
+extend-exclude = [".venv", ".zcode", "templates", "static", "data"]
+
+[tool.ruff.lint]
+# E/F 基础错误、I 导入排序、B bugbear、UP 升级、ASYNC 异步陷阱、S 安全、RUF
+select = ["E", "F", "W", "I", "B", "UP", "C4", "ASYNC", "S", "RUF"]
+ignore = [
+    "E501",    # 行宽交给 formatter，不强制
+    "E402",    # main.py 存在「先定义后 import」的历史结构，迁移期暂放行
+    "S101",    # 生产代码外的 assert（测试/断言脚本）
+    "S104",    # 绑定 0.0.0.0（服务端有意为之）
+    "S110",    # try/except/pass（本项目大量「失败静默降级」策略，见交接文档）
+    "S112",    # try/except/continue
+    "S324",    # hashlib.md5 用于非安全场景（上游签名口径）
+    "S603", "S607",  # subprocess（打包/运维脚本）
+    "UP009",   # 保留 `# -*- coding: utf-8 -*-` 文件头（全项目既有约定）
+    "RUF001", "RUF002", "RUF003",  # 全角字符（中文注释/文案，误报）
+]
+
+[tool.ruff.lint.per-file-ignores]
+"tests/**" = ["S", "ASYNC"]
+".zcode/**" = ["S", "ASYNC", "F"]
+"_mkpkg.py" = ["S"]
+# ASYNC109：timeout 参数是有意 API——直接转发给 aiohttp 的 ClientTimeout，
+# 不是「用 sleep 当超时」的反模式。
+"core/http_client.py" = ["ASYNC109"]
+
+[tool.ruff.lint.isort]
+known-first-party = ["core", "web", "music_api", "auth_system"]
+
+[tool.ruff.format]
+quote-style = "preserve"
+
+# ============ Pyright：类型检查 ============
+[tool.pyright]
+include = ["core", "web"]
+exclude = [".venv", ".zcode", "data", "downloads", "templates", "static"]
+venvPath = "."
+venv = ".venv"
+pythonVersion = "3.12"
+typeCheckingMode = "basic"
+# 迁移期口径：存量 Flask 巨石（main.py/auth_*.py）暂不纳入严格检查，
+# 新写的 core/ 与 web/ 要求类型干净。随迁移推进逐步把模块移入 include。
+reportMissingImports = true
+reportOptionalMemberAccess = "warning"
+reportAttributeAccessIssue = "warning"
+reportGeneralTypeIssues = "warning"
+
+# ============ Pytest ============
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+testpaths = ["tests"]
+addopts = "-q"

requirements-dev.txt

@@ -0,0 +1,6 @@
+# 开发依赖（开发/CI 专用，不进生产镜像）
+pytest>=8.0
+pytest-asyncio>=0.24
+ruff>=0.6
+pyright>=1.1.390
+httpx>=0.27

requirements-fastapi.txt

@@ -1,5 +1,14 @@
-# FastAPI 迁移目标依赖（当前生产仍以 Flask + waitress 运行，本文件不影响既有部署）
+# 生产运行时依赖（FastAPI 版）
-# 待阶段 C 切换生产服务器后，合并进 requirements.txt 并移除 Flask 相关项。
+# 口径同旧 requirements.txt：加版本上界，防上游大版本静默破坏（第 95 条 P2-6）。
-# 版本上界口径同 requirements.txt（第 95 条 P2-6：防上游大版本静默破坏）。
+#
+# 迁移说明：本文件是 FASTAPI 目标栈。当前仓库同时保留 requirements.txt（Flask 旧栈）
+# 直到路由全部迁移完成、生产服务器切换为止，两者可并存。
 fastapi>=0.115,<1.0
-uvicorn>=0.30,<1.0
+uvicorn[standard]>=0.30,<1.0
+aiohttp>=3.10,<4.0
+aiosqlite>=0.20,<1.0
+aiofiles>=24.1
+itsdangerous>=2.2,<3.0
+cryptography>=50.0,<51.0
+qrcode>=7.0,<8.3
+python-multipart>=0.0.9

tests/test_db.py

@@ -0,0 +1,79 @@
+# -*- coding: utf-8 -*-
+"""异步 SQLite 层测试：读写并发、WAL、事务原子性。"""
+
+import asyncio
+
+import pytest
+
+import core.db as db
+
+
+@pytest.fixture()
+def temp_db(tmp_path, monkeypatch):
+    """把 DB 指向临时目录，独立于生产 data/site.db。"""
+    monkeypatch.setattr(db, 'DATA_DIR', tmp_path)
+    monkeypatch.setattr(db, 'DB_PATH', tmp_path / 'site.db')
+    return tmp_path / 'site.db'
+
+
+async def test_write_then_read(temp_db):
+    await db.execute('CREATE TABLE t (id INTEGER PRIMARY KEY, v TEXT)')
+    rid = await db.execute('INSERT INTO t (v) VALUES (?)', ('hello',))
+    assert rid == 1
+    row = await db.fetch_one('SELECT v FROM t WHERE id=?', (1,))
+    assert row['v'] == 'hello'
+    assert await db.fetch_val('SELECT COUNT(*) FROM t') == 1
+
+
+async def test_wal_mode_enabled(temp_db):
+    await db.execute('CREATE TABLE t (id INTEGER PRIMARY KEY)')
+    mode = await db.fetch_val('PRAGMA journal_mode')
+    assert str(mode).lower() == 'wal'
+
+
+async def test_concurrent_read_write(temp_db):
+    """核心诉求：写的同时读不被阻塞、且读到一致快照（WAL 快照隔离）。"""
+    await db.execute('CREATE TABLE nums (id INTEGER PRIMARY KEY, v INTEGER)')
+
+    stop = asyncio.Event()
+    read_errors = []
+    write_count = 0
+
+    async def writer():
+        nonlocal write_count
+        for i in range(200):
+            await db.execute('INSERT INTO nums (v) VALUES (?)', (i,))
+            write_count += 1
+        stop.set()
+
+    async def reader():
+        # 写入过程中持续读，不应抛 SQLITE_BUSY / 不应被阻塞致死
+        while not stop.is_set():
+            try:
+                n = await db.fetch_val('SELECT COUNT(*) FROM nums')
+                assert isinstance(n, int)
+            except Exception as e:
+                read_errors.append(e)
+            await asyncio.sleep(0)
+
+    await asyncio.gather(writer(), *[reader() for _ in range(4)])
+
+    assert not read_errors, f'读期间出现异常: {read_errors[:3]}'
+    assert write_count == 200
+    assert await db.fetch_val('SELECT COUNT(*) FROM nums') == 200
+
+
+async def test_write_transaction_commit_and_rollback(temp_db):
+    await db.execute('CREATE TABLE t (id INTEGER PRIMARY KEY, v TEXT)')
+
+    async with db.write_transaction() as conn:
+        await conn.execute('INSERT INTO t (v) VALUES (?)', ('a',))
+        await conn.execute('INSERT INTO t (v) VALUES (?)', ('b',))
+    assert await db.fetch_val('SELECT COUNT(*) FROM t') == 2
+
+    with pytest.raises(RuntimeError):
+        async with db.write_transaction() as conn:
+            await conn.execute('INSERT INTO t (v) VALUES (?)', ('c',))
+            raise RuntimeError('boom')
+    # 回滚：c 不应落库
+    assert await db.fetch_val('SELECT COUNT(*) FROM t') == 2

tests/test_http_client.py

@@ -0,0 +1,113 @@
+# -*- coding: utf-8 -*-
+"""异步 HTTP 客户端测试：连接复用、有界重试、4xx 不重试、响应体上限。"""
+
+import pytest
+from aiohttp import web
+
+from core.http_client import AsyncHTTPClient, UpstreamHTTPError, UpstreamTooLarge
+
+
+@pytest.fixture()
+async def server():
+    """本地 aiohttp 测试服务器。"""
+    hits = {'flaky': 0}
+
+    async def ok(request):
+        return web.json_response({'ok': True})
+
+    async def flaky(request):
+        # 首次 500，之后 200 —— 验证 5xx 退避重试
+        hits['flaky'] += 1
+        if hits['flaky'] == 1:
+            return web.Response(status=500, text='boom')
+        return web.json_response({'retried': True})
+
+    async def notfound(request):
+        return web.Response(status=404, text='nope')
+
+    async def big(request):
+        return web.Response(body=b'x' * (2 * 1024 * 1024))
+
+    app = web.Application()
+    app.router.add_get('/ok', ok)
+    app.router.add_get('/flaky', flaky)
+    app.router.add_get('/notfound', notfound)
+    app.router.add_get('/big', big)
+
+    runner = web.AppRunner(app)
+    await runner.setup()
+    site = web.TCPSite(runner, '127.0.0.1', 0)
+    await site.start()
+    port = site._server.sockets[0].getsockname()[1]
+    base = f'http://127.0.0.1:{port}'
+    try:
+        yield base, hits
+    finally:
+        await runner.cleanup()
+
+
+async def test_get_json(server):
+    base, _ = server
+    c = AsyncHTTPClient()
+    try:
+        assert await c.get_json(base + '/ok') == {'ok': True}
+    finally:
+        await c.close()
+
+
+async def test_retry_on_5xx(server):
+    base, hits = server
+    c = AsyncHTTPClient()
+    try:
+        data = await c.get_json(base + '/flaky')
+        assert data == {'retried': True}
+        assert hits['flaky'] == 2  # 第一次 500 + 重试成功
+    finally:
+        await c.close()
+
+
+async def test_no_retry_on_4xx(server):
+    base, _ = server
+    c = AsyncHTTPClient()
+    try:
+        with pytest.raises(UpstreamHTTPError) as ei:
+            await c.get_text(base + '/notfound')
+        assert ei.value.status == 404
+    finally:
+        await c.close()
+
+
+async def test_response_size_limit(server):
+    base, _ = server
+    c = AsyncHTTPClient(max_bytes=1024 * 1024)  # 1MB 上限，服务端返回 2MB
+    try:
+        with pytest.raises(UpstreamTooLarge):
+            await c.get_text(base + '/big')
+    finally:
+        await c.close()
+
+
+async def test_session_reuse(server):
+    """同一客户端多次请求复用同一（按 loop 隔离的）session —— 连接池生效。"""
+    base, _ = server
+    c = AsyncHTTPClient()
+    try:
+        await c.get_json(base + '/ok')
+        s1 = await c._session_for_loop()
+        await c.get_json(base + '/ok')
+        s2 = await c._session_for_loop()
+        assert s1 is s2 and not s1.closed
+    finally:
+        await c.close()
+
+
+async def test_stream(server):
+    base, _ = server
+    c = AsyncHTTPClient()
+    try:
+        async with c.stream('GET', base + '/ok') as resp:
+            assert resp.status == 200
+            body = await resp.read()
+            assert b'ok' in body
+    finally:
+        await c.close()

web/app.py

@@ -12,6 +12,7 @@
 两套独立进程语义。生产切换前需按计划把状态与任务模型统一（见迁移计划阶段 C），
 当前仅用于开发期联调。
 """
+
 from fastapi import FastAPI
 
 from core.config import APP_VERSION
@@ -40,5 +41,7 @@ def create_app(serve_flask_fallback: bool = False) -> FastAPI:
 def _mount_flask_fallback(app: FastAPI) -> None:
     """把遗留 Flask WSGI 应用挂到根路径，兜底未迁移的路由。"""
     from starlette.middleware.wsgi import WSGIMiddleware
+
     import main as legacy_flask
+
     app.mount('/', WSGIMiddleware(legacy_flask.app))

web/main.py

@@ -4,6 +4,7 @@
 开发期启动：  .venv/Scripts/python.exe web/main.py
 生产切换前需先将状态/任务模型与既有 Flask 进程统一（见迁移计划阶段 C）。
 """
+
 import os
 import sys
 

web/response.py

@@ -7,6 +7,7 @@ FastAPI 侧改为直接返回 JSONResponse，但**包体结构完全一致**：
     error:   {"status": sc, "success": false, "message": msg, ["error_code": ...]}
 这样前端无需任何改动即可同时对接两个框架。
 """
+
 from typing import Any
 
 from fastapi.responses import JSONResponse
@@ -24,7 +25,7 @@ def success(data: Any = None, message: str = 'success', status_code: int = 200)
     return JSONResponse(content=body, status_code=status_code)
 
 
-def error(message: str, status_code: int = 400, error_code: str = None) -> JSONResponse:
+def error(message: str, status_code: int = 400, error_code: str | None = None) -> JSONResponse:
     """错误响应（对应 Flask APIResponse.error）"""
     body = {
         'status': status_code,

web/routers/system.py

@@ -5,6 +5,7 @@
 此处实现与 main.py 的 health_check / api_info **响应契约逐字段对齐**，
 用于验证双框架一致性（见 .zcode/refactor/parity.py）。
 """
+
 import sys
 import time
 
@@ -41,6 +42,7 @@ def health_check():
     """健康检查API（对应 Flask health_check）"""
     try:
         from music_api import load_cookies
+
         cookies = load_cookies()
         cookie_status = 'valid' if cookies else 'invalid'
 
@@ -49,7 +51,7 @@ def health_check():
             'timestamp': int(time.time()) if 'time' in sys.modules else None,
             'cookie_status': cookie_status,
             'cookie_count': len(cookies),
-            'downloads_dir': 'configured',   # R5-P3：不向匿名访客回显服务器绝对路径
+            'downloads_dir': 'configured',  # R5-P3：不向匿名访客回显服务器绝对路径
             'version': APP_VERSION,
         }
         return success(health_info, "API服务运行正常")
@@ -66,10 +68,7 @@ def api_info():
             'version': APP_VERSION,
             'description': '云村小助手 · 网易云音乐解析/下载服务',
             'endpoints': dict(_ENDPOINTS),
-            'supported_qualities': [
+            'supported_qualities': ['standard', 'exhigh', 'lossless', 'hires', 'sky', 'jyeffect', 'jymaster', 'dolby'],
-                'standard', 'exhigh', 'lossless',
-                'hires', 'sky', 'jyeffect', 'jymaster', 'dolby'
-            ],
             'config': {
                 'downloads_dir': 'configured',
                 'max_body_bytes': '2MB（备份上传 200MB）',