feat: Android download page, analysis retry and a collapsible search

- /android is a public page with the latest APK, the server address to copy
  and three install steps; linked from the sign-in screen and the profile menu
- failed audio analysis can be retried from the library page, which also shows
  the most common error; the analyzer no longer burns attempts on files that
  are missing because the disk is not mounted
- the top bar search folds into a round button and slides open on click, "/"
  or Ctrl+K

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/pages/AppDownloadPage.tsx

@@ -0,0 +1,70 @@
+import { useQuery } from '@tanstack/react-query';
+import { useState } from 'react';
+import { useTranslation } from 'react-i18next';
+
+import { useSession } from '../app/session';
+import { formatBytes } from '../shared/lib/format';
+import { checkIcon, copyIcon, downloadIcon } from '../shared/ui/icons';
+import { Icon } from '../shared/ui/ui';
+import { AuthLayout } from './AuthLayout';
+import s from './auth.module.css';
+
+/**
+ * Публичная страница Android-приложения (/android): ссылку можно просто отправить человеку.
+ * APK — последний релиз, который сервер сам берёт из Gitea (docs/mobile.md#самообновление).
+ */
+export function AppDownloadPage() {
+  const { t, i18n } = useTranslation(['auth', 'common']);
+  const session = useSession();
+  const [copied, setCopied] = useState(false);
+  const latest = useQuery({
+    queryKey: ['android-latest'],
+    queryFn: async () => (await session.client.GET('/api/v1/app/android/latest')).data ?? null,
+    staleTime: 10 * 60_000,
+  });
+  const server = location.origin;
+  const copy = () =>
+    void navigator.clipboard?.writeText(server).then(() => {
+      setCopied(true);
+      setTimeout(() => setCopied(false), 1500);
+    });
+  const r = latest.data;
+
+  return (
+    <AuthLayout footer={<a href="/login">{t('app.to_login')}</a>}>
+      <span className={s.badge}>Android</span>
+      <h1>{t('app.title')}</h1>
+      <p className={s.lead}>{t('app.subtitle')}</p>
+      {latest.isPending ? null : r ? (
+        <>
+          <a className={s.download} href={r.download_url} download>
+            <Icon src={downloadIcon} size={22} />
+            <span>
+              {t('app.download')}
+              <span className={s.downloadMeta}>
+                {t('app.version', { version: r.version })} · {formatBytes(r.size, i18n.language)}
+              </span>
+            </span>
+          </a>
+          <ol className={s.steps}>
+            <li>{t('app.step_install')}</li>
+            <li>
+              {t('app.step_server')}
+              <button type="button" className={s.server} onClick={copy} aria-label={t('app.copy_server')}>
+                <code>{server}</code>
+                <Icon src={copied ? checkIcon : copyIcon} size={16} />
+              </button>
+            </li>
+            <li>{t('app.step_updates')}</li>
+          </ol>
+          <details className={s.details}>
+            <summary>{t('app.checksum')}</summary>
+            <code>{r.sha256}</code>
+          </details>
+        </>
+      ) : (
+        <div className={s.hint}>{t('app.unavailable')}</div>
+      )}
+    </AuthLayout>
+  );
+}

apps/web/src/pages/LoginPage.tsx

@@ -37,7 +37,15 @@ export function LoginPage() {
   };
 
   return (
-    <AuthLayout footer={info.data ? `pipu ${info.data.version}` : undefined}>
+    <AuthLayout
+      footer={
+        info.data ? (
+          <>
+            pipu {info.data.version} · <a href="/android">{t('app.link')}</a>
+          </>
+        ) : undefined
+      }
+    >
       <h1>{t('login.title')}</h1>
       <p className={s.lead}>{t('login.subtitle')}</p>
       {info.data?.bootstrap_required && <div className={s.hint}>{t('login.bootstrap_hint')}</div>}

apps/web/src/pages/admin/LibraryPage.tsx

@@ -1,5 +1,5 @@
 import { unwrap } from '@pipu/core';
-import { useMutation, useQuery } from '@tanstack/react-query';
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
 import { useId } from 'react';
 import { useTranslation } from 'react-i18next';
 
@@ -32,6 +32,11 @@ export function LibraryPage() {
   const reindex = useMutation({
     mutationFn: async () => unwrap(await session.client.POST('/api/v1/admin/search/reindex')),
   });
+  const queryClient = useQueryClient();
+  const retry = useMutation({
+    mutationFn: async () => unwrap(await session.client.POST('/api/v1/admin/library/analysis/retry')),
+    onSuccess: () => void queryClient.invalidateQueries({ queryKey: ['library-status'] }),
+  });
   const d = status.data;
   const tiles = d
     ? ([
@@ -77,7 +82,19 @@ export function LibraryPage() {
               total: d.analysis.done + d.analysis.queued + d.analysis.running + d.analysis.failed,
             })}
           />
-          {d.analysis.failed > 0 && <span className={l.scanError}>{t('library.analysis_failed', { count: d.analysis.failed })}</span>}
+          {d.analysis.failed > 0 && (
+            <div className={l.retryRow}>
+              <span className={l.scanError}>
+                {t('library.analysis_failed', { count: d.analysis.failed })}
+                {d.analysis.top_error && <span className={l.errorDetail}>{d.analysis.top_error}</span>}
+              </span>
+              {admin && (
+                <Button variant="secondary" icon={refreshIcon} busy={retry.isPending} onClick={() => retry.mutate()}>
+                  {t('library.analysis_retry')}
+                </Button>
+              )}
+            </div>
+          )}
           {d.analysis.analyzer_ver && <span className={l.scanSummary}>{t('library.analyzer', { ver: d.analysis.analyzer_ver })}</span>}
         </section>
       )}

apps/web/src/pages/admin/library.module.css

@@ -118,6 +118,20 @@
   color: var(--danger);
 }
 
+.retryRow {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 16px;
+}
+
+.errorDetail {
+  display: block;
+  margin-top: 4px;
+  color: var(--text3);
+  word-break: break-word;
+}
+
 .bar {
   height: 6px;
   border-radius: 3px;

apps/web/src/pages/auth.module.css

@@ -161,6 +161,83 @@
   color: var(--text3);
 }
 
+.footer a {
+  color: var(--text2);
+}
+
+/* Страница Android-приложения (/android). */
+.download {
+  display: flex;
+  align-items: center;
+  gap: 14px;
+  padding: 14px 18px;
+  border-radius: var(--radius-lg);
+  background: var(--accent-fill);
+  color: #fff;
+  font-weight: 700;
+  text-decoration: none;
+  box-shadow: var(--glow);
+  transition:
+    background 0.2s,
+    transform 0.15s;
+}
+
+.download:hover {
+  background: var(--accent-fill2);
+}
+
+.download:active {
+  transform: scale(0.98);
+}
+
+.downloadMeta {
+  display: block;
+  margin-top: 2px;
+  font-size: 12px;
+  font-weight: 500;
+  opacity: 0.85;
+}
+
+.steps {
+  margin: 0;
+  padding-left: 20px;
+  display: flex;
+  flex-direction: column;
+  gap: 10px;
+  color: var(--text2);
+  font-size: 14px;
+  line-height: 1.5;
+}
+
+.server {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  margin-left: 6px;
+  padding: 2px 10px;
+  border-radius: 8px;
+  border: 1px solid var(--line2);
+  background: var(--surface2);
+  color: var(--text);
+  cursor: pointer;
+}
+
+.details {
+  font-size: 12px;
+  color: var(--text3);
+}
+
+.details summary {
+  cursor: pointer;
+}
+
+.details code {
+  display: block;
+  margin-top: 6px;
+  word-break: break-all;
+  font-family: var(--font-mono);
+}
+
 .link {
   align-self: center;
 }