fix(frontend): resolve all eslint errors to zero (B1)

frontend/eslint.config.js

@@ -35,6 +35,9 @@ export default tseslint.config(
       "jsx-a11y/click-events-have-key-events": "warn",
       "jsx-a11y/no-static-element-interactions": "warn",
       "jsx-a11y/no-noninteractive-element-interactions": "warn",
+      // 键盘焦点容器:CBZ/PDF 阅读器根 div 用 tabIndex={0} 接方向键翻页,
+      // 与上面三条同属 ② 改版范围（radix 原语自带焦点管理），本期随块降 warn
+      "jsx-a11y/no-noninteractive-tabindex": "warn",
     },
   },
   {

frontend/src/auth/AuthContext.tsx

@@ -40,6 +40,7 @@ export function AuthProvider({ children }: { children: ReactNode }) {
   useEffect(() => {
     if (token && meQ.isError) {
       setToken(null); // 非 401 失败也要清持久化 token，避免与 React 状态分叉导致 RequireAuth 永久加载
+      // eslint-disable-next-line react-hooks/set-state-in-effect -- 对「me 查询失败」异步结果的清理反应,与持久化 token 需同帧回收;改渲染期重置/事件驱动会改变鉴权失败时序,保守保留
       setTok(null);
     }
   }, [token, meQ.isError]);

frontend/src/components/Cover.tsx

@@ -12,12 +12,18 @@ export function useAuthedImage(url: string | undefined): { src: string; failed:
   });
   const [nonce, setNonce] = useState(0);
   const key = (url ?? "") + "#" + nonce;
+  // url/nonce 变化时先落回占位态:React 官方推荐的「渲染期按下发 key 重置本地 state」,
+  // 替代原先 effect 内的同步 setState(级联渲染),行为等价——加载中同样呈现 src="" 的占位
+  const [prevKey, setPrevKey] = useState(key);
+  if (prevKey !== key) {
+    setPrevKey(key);
+    setState({ key, src: "", failed: false });
+  }
 
   useEffect(() => {
     if (!url) return;
     let dead = false;
     const k = url + "#" + nonce;
-    setState({ key: k, src: "", failed: false });
     fetchObjectUrl(url)
       .then((src) => !dead && setState({ key: k, src, failed: false }))
       .catch(() => !dead && setState({ key: k, src: "", failed: true }));

frontend/src/pages/Login.tsx

@@ -51,6 +51,7 @@ export default function Login() {
                 id="login-user"
                 value={u}
                 onChange={(e) => setU(e.target.value)}
+                // eslint-disable-next-line jsx-a11y/no-autofocus -- 登录页整页即表单,首字段自动聚焦是通行 UX;规则无按场景豁免选项,保留行为
                 autoFocus
                 autoComplete="username"
               />

frontend/src/pages/Shelf.tsx

@@ -141,7 +141,13 @@ export default function Shelf() {
   const [qRaw, setQRaw] = useState(serverQ);
   const [confirmDel, setConfirmDel] = useState<Book | null>(null);
 
-  useEffect(() => setQRaw(serverQ), [serverQ]);
+  // URL 是筛选词的事实来源:回退/前进/程序化改参时把输入框拉回 URL 值。
+  // 用 React 官方推荐的「渲染期按下发值重置本地 state」替代原先 effect 内的同步 setState
+  const [prevServerQ, setPrevServerQ] = useState(serverQ);
+  if (prevServerQ !== serverQ) {
+    setPrevServerQ(serverQ);
+    setQRaw(serverQ);
+  }
   useEffect(() => {
     if (qRaw.trim() === serverQ) return;
     const t = setTimeout(() => {
@@ -284,6 +290,7 @@ export default function Shelf() {
       {continueRows.length > 0 && !searching && (
         <section className="mb-8">
           <h2 className="mb-3 text-sm font-medium text-muted-foreground">继续阅读</h2>
+          {/* eslint-disable-next-line jsx-a11y/no-redundant-roles -- Tailwind preflight 移除了 ul 的 list 样式,Safari/VoiceOver 因此丢列表语义;role="list" 是官方推荐的补偿写法,非冗余 */}
           <ul className="flex gap-3 overflow-x-auto pb-2" role="list">
             {continueRows.map((r, i) => {
               const b = booksByKey.get(`${r.library_id}/${r.path}`);

frontend/src/readers/CbzReader.tsx

@@ -38,10 +38,17 @@ function PageImg({ url, width, onLoaded }: { url: string; width: number; onLoade
   const [src, setSrc] = useState("");
   const [failed, setFailed] = useState(false);
   const [nonce, setNonce] = useState(0);
-  useEffect(() => {
-    let dead = false;
+  // url/nonce 变化时先落回占位态:React 官方推荐的「渲染期按下发 key 重置本地 state」,
+  // 替代原先 effect 内的同步 setState(级联渲染);换页/重试时的表现与原先一致
+  const key = url + "#" + nonce;
+  const [prevKey, setPrevKey] = useState(key);
+  if (prevKey !== key) {
+    setPrevKey(key);
     setSrc("");
     setFailed(false);
+  }
+  useEffect(() => {
+    let dead = false;
     fetchObjectUrl(url)
       .then((s) => !dead && setSrc(s))
       .catch(() => !dead && setFailed(true));

frontend/src/readers/EpubReader.tsx

@@ -38,12 +38,19 @@ export default function EpubReader({ book, initialLocator, initialPercent }: Rea
   const [err, setErr] = useState("");
   const [nonce, setNonce] = useState(0);
   const [ready, setReady] = useState(false);
+  // 重新加载(换书/重试)时先清错误与就绪态:React 官方推荐的「渲染期按下发 key 重置本地 state」,
+  // 替代原先 effect 内的同步 setState(级联渲染);首挂载 key 相等,重置为空操作,行为等价
+  const loadKey = (book.file_url ?? "") + "#" + nonce;
+  const [prevLoadKey, setPrevLoadKey] = useState(loadKey);
+  if (prevLoadKey !== loadKey) {
+    setPrevLoadKey(loadKey);
+    setErr("");
+    setReady(false);
+  }
 
   useEffect(() => {
     let dead = false;
     let bookObj: EpubBookLike | null = null;
-    setErr("");
-    setReady(false);
     (async () => {
       const ePub = await loadEpub();
       const buf = await apiRaw(book.file_url ?? "").then((r) => r.arrayBuffer());

frontend/src/readers/PdfReader.tsx

@@ -28,10 +28,17 @@ export default function PdfReader({ book, initialLocator, initialPercent }: Read
   const [err, setErr] = useState("");
   const [nonce, setNonce] = useState(0); // 仅加载重试
   const [redraw, setRedraw] = useState(0); // 仅 resize 重绘(不重新下载文档)
+  // 重新加载(换书/重试)时先清错误:React 官方推荐的「渲染期按下发 key 重置本地 state」,
+  // 替代原先 effect 内的同步 setState(级联渲染);首挂载 key 相等,重置为空操作,行为等价
+  const loadKey = (book.file_url ?? "") + "#" + nonce;
+  const [prevLoadKey, setPrevLoadKey] = useState(loadKey);
+  if (prevLoadKey !== loadKey) {
+    setPrevLoadKey(loadKey);
+    setErr("");
+  }
 
   useEffect(() => {
     let dead = false;
-    setErr("");
     (async () => {
       const buf = await apiRaw(book.file_url ?? "").then((r) => r.arrayBuffer());
       if (dead) return;

frontend/src/readers/TextReader.tsx

@@ -19,10 +19,17 @@ function useFileText(url: string) {
   const [text, setText] = useState<string | null>(null);
   const [err, setErr] = useState("");
   const [nonce, setNonce] = useState(0);
-  useEffect(() => {
-    let dead = false;
+  // url/nonce 变化时先落回加载态:React 官方推荐的「渲染期按下发 key 重置本地 state」,
+  // 替代原先 effect 内的同步 setState(级联渲染);重试时的表现与原先一致
+  const key = url + "#" + nonce;
+  const [prevKey, setPrevKey] = useState(key);
+  if (prevKey !== key) {
+    setPrevKey(key);
     setText(null);
     setErr("");
+  }
+  useEffect(() => {
+    let dead = false;
     apiRaw(url)
       .then((r) => r.arrayBuffer())
       .then((b) => !dead && setText(decodeText(b)))
@@ -238,6 +245,7 @@ function TxtView({ book, initialLocator, initialPercent, chrome }: ReaderProps)
     const rawCh = Number(initialLocator?.ch);
     if (Number.isFinite(rawCh) && rawCh >= 0 && rawCh < chapters.length) {
       targetCi.current = Math.floor(rawCh);
+      // eslint-disable-next-line react-hooks/set-state-in-effect -- 首章渲染后按缓存 locator 落位阅读进度;ci 与下方滚动定位 effect/refs 协作,改渲染期重置属高风险重构,保守保留
       setCi(Math.floor(rawCh));
       if (hasF) restoreFrac.current = f;
     } else if (hasF) {