Release v0.51.30 — Release G (offline recovery + PWA hardening + opt-in session jump buttons + opt-in endless-scroll)

Merge stage-325 to master.
2026-05-25 19:20:16 +00:00 · 2026-05-08 14:37:53 -07:00
parent 596c6b314d bc4421a1b6
commit 0b7e1e60e8
19 changed files with 684 additions and 36 deletions
@@ -1,6 +1,39 @@
 # Hermes Web UI -- Changelog

-## [v0.51.29] — 2026-05-08 — 6-PR contributor batch (Release F: Docker hardening + login persistence + scroll/lineage fixes + i18n cleanup)
+## [v0.51.30] — 2026-05-08 — 3-PR contributor batch (Release G: offline recovery + PWA hardening + opt-in session jump buttons + opt-in endless-scroll)
+
+### Added (3 PRs, all from @ai-ag2026)
+
+- **PR #1891** — Browser offline recovery and PWA cache hardening. Adds an offline/recovery banner that probes `/health` and auto-refreshes when Hermes is reachable again. Defers stream error handling while the browser is offline so reconnecting does not immediately surface a terminal chat error. Makes service-worker shell assets network-first with cache fallback (so local hotfixes are not hidden behind stale cached JS/CSS), while preserving offline-launch capability via `install` pre-caching of SHELL_ASSETS. Keeps PWA/native chrome colors aligned with the dark Hermes background. Stream-error deferral only triggers when the banner is visible OR `navigator.onLine===false` — so Hermes-up + browser-online flows errors through normally; no swallowed auth errors. Supersedes the recovery/PWA portion of #1888.
+
+- **PR #1928** — Opt-in session Start/End jump buttons (`session_jump_buttons` setting, default OFF). Adds an Appearance setting that surfaces a sticky `Start` pill (loads full history and jumps to beginning) and expands the existing scroll-to-bottom button into an `End` pill. Localized text, tooltip, and aria labels for the jump controls. The opt-in default keeps the existing UI unchanged for users who don't want the floating pills.
+
+- **PR #1929** — Opt-in session endless-scroll (`session_endless_scroll` setting, default OFF). Adds automatic prefetching of older transcript pages while scrolling upward (1.5x viewport prefetch window). Builds on #1927's viewport-preservation fix (shipped in v0.51.29) so prepended pages have scroll runway and don't jump. Replaces the previous auto-trigger-at-scrollTop<80 behavior — when the setting is OFF, users get the manual "Load earlier" button path (`_wireMessageWindowLoadEarlierButton`).
+
+### Conflict resolution applied during stage merge
+
+#1928 and #1929 both touch `static/ui.js`, `static/i18n.js`, `static/index.html`, `static/panels.js`, `api/config.py`. Mechanical conflicts (both add new settings keys / locale entries / HTML toggles / accessor branches) were resolved by keeping both — the features are independent opt-in toggles. The `static/ui.js` scroll-listener conflict required an intent-based resolution: #1929 INTENTIONALLY replaces the `el.scrollTop<80` auto-trigger block with the gated prefetch block, so the old block was removed. Test `tests/test_session_endless_scroll.py::test_scroll_listener_prefetches_older_messages_only_when_enabled` enforces this. CHANGELOG conflicts auto-resolved during rebase (took ours strategy).
+
+### Tests
+
+4960 → **4977 collected, 4977 passing, 0 regressions** (+17 net new). Full suite ~140s on Python 3.11 (HERMES_HOME isolated). JS syntax check (`node -c`) clean on all 6 modified `static/*.js` files. Browser API sanity harness (port 8789): all 11 endpoints + 20 QA tests PASS. **Manual browser verification on stage-325 server** (port 8789): both new settings toggles render in the Settings panel; `window._isSessionEndlessScrollEnabled()` correctly reflects toggle state; `_updateSessionStartJumpButton` function is exposed; offline-banner template + "Check now" button present in HTML. Opus advisor: SHIP-WITH-FIXES (one tracked race fast-follow + one i18n polish fast-follow, both non-blockers per Opus's own recommendation "Ship the batch").
+
+### Pre-release verification
+
+- Full pytest under `HERMES_HOME` isolation: **4977 passed, 8 skipped, 1 xfailed, 2 xpassed, 8 subtests passed** in 140.56s.
+- Browser API harness against stage-325 on port 8789: all 11 endpoints + 20 QA tests PASS (111.35s for QA phase).
+- Manual browser verification: stage-325 server up on 8789, navigated to /, verified new toggles render in Settings panel, verified helper functions exposed correctly, verified offline-banner template loaded.
+- `node -c` on all 6 modified `static/*.js` files: clean.
+- Stage diff: 16 files, +649/-30.
+- Opus advisor pass on stage-325 brief: VERDICT=SHIP-WITH-FIXES with explicit "Ship the batch" recommendation. Two fast-follows filed for tracking, neither is blocking.
+- v0.51.29 carry-overs verified preserved (no in-batch changes to `_strip_workspace_prefix`, `evaluate_goal_after_turn`, `_profiles_match`, `mcp_server.py`).
+- Pre-stamp re-fetch of all 3 PR heads: no contributor force-push during Opus window.
+
+### Follow-up items filed (non-blocking)
+
+- **Race between endless-scroll prefetch and Start-jump's `_ensureAllMessagesLoaded`** — with both opt-ins ON, an in-flight prefetch (started by 1.5x-viewport trigger) racing with `jumpToSessionStart` → `_ensureAllMessagesLoaded` could produce duplicate messages if the prefetch resolves last. Narrow window, but the fix is to gate `_ensureAllMessagesLoaded` on the existing `_loadingOlder` flag.
+- **#1928 locale parity** — `session_jump_*` and `settings_*_session_jump_buttons` keys are English literals in ja/ru/es/de/zh/zh-Hant/pt/ko. Default-OFF + English fallback works, but breaks the locale-parity standard set by #1929 and #1891 in the same release.
+

 ### Added (1 PR)

@@ -2,7 +2,7 @@

 > Web companion to the Hermes Agent CLI. Same workflows, browser-native.
 >
-> Last updated: v0.51.29 (May 8, 2026) — 4960 tests collected — 6-PR Release F batch (Docker hardening + login persistence + scroll/lineage fixes + i18n cleanup)
+> Last updated: v0.51.30 (May 8, 2026) — 4977 tests collected — 3-PR Release G batch (offline recovery + PWA hardening + opt-in session jump buttons + opt-in endless-scroll)
 > Test source: `pytest tests/ --collect-only -q`
 > Per-version detail: see [CHANGELOG.md](./CHANGELOG.md)

@@ -1835,8 +1835,8 @@ Bridged CLI sessions:

 ---

-*Last updated: v0.51.29, May 8, 2026*
-*Total automated tests collected: 4960*
+*Last updated: v0.51.30, May 8, 2026*
+*Total automated tests collected: 4977*
 *Regression gate: tests/test_regressions.py*
 *Run: pytest tests/ -v --timeout=60*
 *Source: <repo>/*
@@ -19,7 +19,7 @@ logger = logging.getLogger(__name__)

 # ── Public paths (no auth required) ─────────────────────────────────────────
 PUBLIC_PATHS = frozenset({
-    '/login', '/health', '/favicon.ico',
+    '/login', '/health', '/favicon.ico', '/sw.js',
    '/api/auth/login', '/api/auth/status',
    '/manifest.json', '/manifest.webmanifest',
 })
@@ -3682,6 +3682,8 @@ _SETTINGS_DEFAULTS = {
    "theme": "dark",  # light | dark | system
    "skin": "default",  # accent color skin: default | ares | mono | slate | poseidon | sisyphus | charizard
    "font_size": "default",  # small | default | large
+    "session_jump_buttons": False,  # show Start/End transcript jump pills
+    "session_endless_scroll": False,  # auto-load older transcript pages while scrolling upward
    "language": "en",  # UI locale code; must match a key in static/i18n.js LOCALES
    "bot_name": os.getenv(
        "HERMES_WEBUI_BOT_NAME", "Hermes"
@@ -3810,6 +3812,8 @@ _SETTINGS_BOOL_KEYS = {
    "show_thinking",
    "simplified_tool_calling",
    "api_redact_enabled",
+    "session_jump_buttons",
+    "session_endless_scroll",
 }
 # Language codes are validated as short alphanumeric BCP-47-like tags (e.g. 'en', 'zh', 'fr')
 _SETTINGS_LANG_RE = __import__("re").compile(r"^[a-zA-Z]{2,10}(-[a-zA-Z0-9]{2,8})?$")
@@ -1130,10 +1130,17 @@ function _normalizeAppearance(theme,skin){
 // the meta tag.
 function _syncThemeColorMeta(){
  try{
-    const meta=document.getElementById('hermes-theme-color');
-    if(!meta) return;
    const bg=getComputedStyle(document.documentElement).getPropertyValue('--bg').trim();
-    if(bg) meta.setAttribute('content',bg);
+    if(!bg) return;
+    const known=document.getElementById('hermes-theme-color');
+    if(known){
+      known.setAttribute('content',bg);
+      known.removeAttribute('media');
+    }
+    document.querySelectorAll('meta[name="theme-color"]').forEach(meta=>{
+      meta.setAttribute('content',bg);
+      meta.removeAttribute('media');
+    });
  }catch(e){}
 }

@@ -1303,11 +1310,13 @@ function applyBotName(){
    window._simplifiedToolCalling=s.simplified_tool_calling!==false;
    window._sidebarDensity=(s.sidebar_density==='detailed'?'detailed':'compact');
    window._busyInputMode=(s.busy_input_mode||'queue');
+    window._sessionEndlessScrollEnabled=!!s.session_endless_scroll;
    window._botName=s.bot_name||'Hermes';
    if(s.default_model) window._defaultModel=s.default_model;
    // Persist default workspace so the blank new-chat page can show it
    // and workspace actions (New file/folder) work before the first session (#804).
    if(s.default_workspace) S._profileDefaultWorkspace=s.default_workspace;
+    window._sessionJumpButtonsEnabled=!!s.session_jump_buttons;
    const appearance=_normalizeAppearance(s.theme,s.skin);
    localStorage.setItem('hermes-theme',appearance.theme);
    _applyTheme(appearance.theme);
@@ -1335,8 +1344,10 @@ function applyBotName(){
    window._notificationsEnabled=false;
    window._showThinking=true;
    window._simplifiedToolCalling=true;
+    window._sessionJumpButtonsEnabled=false;
    window._sidebarDensity='compact';
    window._busyInputMode='queue';
+    window._sessionEndlessScrollEnabled=false;
    window._botName='Hermes';
    _bootSettings={check_for_updates:false};
    if(typeof setLocale==='function'){
@@ -5,6 +5,13 @@

 const LOCALES = {
  en: {
+    offline_title: 'Connection lost',
+    offline_browser_detail: 'Your browser reports that this device is offline.',
+    offline_network_detail: 'Hermes is unreachable from this browser right now.',
+    offline_autorefresh: 'I will refresh this page automatically when Hermes is reachable again.',
+    offline_check_now: 'Check now',
+    offline_checking: 'Checking…',
+    offline_stream_waiting: 'Connection lost. Waiting to refresh…',
    _lang: 'en',
    _label: 'English',
    _speech: 'en-US',
@@ -125,6 +132,10 @@ const LOCALES = {
    untitled: 'Untitled',
    n_messages: (n) => `${n} messages`,
    load_older_messages: '↑ Scroll up or click to load older messages',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    queued_label: 'Sends after response',
    queued_count: (n) => n === 1 ? '1 queued' : `${n} queued`,
    queued_cancel: 'Cancel queued message',
@@ -421,6 +432,12 @@ const LOCALES = {
    settings_update_check_failed: 'Update check failed',
    settings_label_workspace_panel_open: 'Keep workspace panel open by default',
    settings_desc_workspace_panel_open: 'When enabled, the workspace / file browser panel opens automatically with each new session. You can still close it manually at any time.',
+    settings_label_session_jump_buttons: 'Show session jump buttons',
+    settings_desc_session_jump_buttons: 'Show floating Start and End buttons while reading long session histories.',
+
+    settings_label_session_endless_scroll: 'Load older messages while scrolling up',
+
+    settings_desc_session_endless_scroll: 'When enabled, older messages load automatically as you scroll upward. When disabled, use the older-messages button.',
    open_in_browser: 'Open in browser',
    settings_dropdown_conversation: 'Conversation',
    settings_dropdown_appearance: 'Appearance',
@@ -1026,6 +1043,13 @@ const LOCALES = {
  },

  ja: {
+    offline_title: '接続が切断されました',
+    offline_browser_detail: 'ブラウザはこのデバイスがオフラインだと報告しています。',
+    offline_network_detail: '現在、このブラウザからHermesに到達できません。',
+    offline_autorefresh: 'Hermesに再接続できたら、このページを自動的に更新します。',
+    offline_check_now: '今すぐ確認',
+    offline_checking: '確認中…',
+    offline_stream_waiting: '接続が切断されました。更新を待っています…',
    _lang: 'ja',
    _label: '日本語',
    _speech: 'ja-JP',
@@ -1146,6 +1170,10 @@ const LOCALES = {
    untitled: '無題',
    n_messages: (n) => `${n} 件のメッセージ`,
    load_older_messages: '↑ 上にスクロール、またはクリックして過去のメッセージを読み込む',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    queued_label: '応答後に送信',
    queued_count: (n) => `${n} 件キュー中`,
    queued_cancel: 'キューに入れたメッセージをキャンセル',
@@ -1442,6 +1470,12 @@ const LOCALES = {
    settings_updates_disabled: 'アップデート確認は無効です',
    settings_label_workspace_panel_open: 'ワークスペースパネルをデフォルトで開いておく',
    settings_desc_workspace_panel_open: '有効にすると、新しいセッションごとにワークスペース/ファイルブラウザパネルが自動で開きます。手動でいつでも閉じられます。',
+    settings_label_session_jump_buttons: 'Show session jump buttons',
+    settings_desc_session_jump_buttons: 'Show floating Start and End buttons while reading long session histories.',
+
+    settings_label_session_endless_scroll: '上スクロールで古いメッセージを読み込む',
+
+    settings_desc_session_endless_scroll: '有効にすると、上にスクロールしたとき古いメッセージを自動で読み込みます。無効の場合は古いメッセージボタンを使います。',
    open_in_browser: 'ブラウザで開く',
    settings_dropdown_conversation: '会話',
    settings_dropdown_appearance: '外観',
@@ -2047,6 +2081,13 @@ const LOCALES = {
  },

  ru: {
+    offline_title: 'Соединение потеряно',
+    offline_browser_detail: 'Браузер сообщает, что это устройство офлайн.',
+    offline_network_detail: 'Hermes сейчас недоступен из этого браузера.',
+    offline_autorefresh: 'Я автоматически обновлю страницу, когда Hermes снова станет доступен.',
+    offline_check_now: 'Проверить сейчас',
+    offline_checking: 'Проверка…',
+    offline_stream_waiting: 'Соединение потеряно. Ожидаю обновления…',
    _lang: 'ru',
    _label: 'Русский',
    _speech: 'ru-RU',
@@ -2145,6 +2186,10 @@ const LOCALES = {
    untitled: 'Без названия',
    n_messages: (n) => `${n} сообщений`,
    load_older_messages: '↑ Прокрутите вверх или нажмите, чтобы загрузить ранние сообщения',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    queued_label: 'Отправить после ответа',
    queued_count: (n) => n === 1 ? '1 в очереди' : `${n} в очереди`,
    queued_cancel: 'Отменить сообщение',
@@ -2880,6 +2925,12 @@ const LOCALES = {
    settings_update_check_failed: 'Ошибка проверки обновлений',
    settings_label_workspace_panel_open: 'Открывать панель рабочей области по умолчанию',
    settings_desc_workspace_panel_open: 'При включении панель файлов будет открываться автоматически в каждой новой сессии.',
+    settings_label_session_jump_buttons: 'Show session jump buttons',
+    settings_desc_session_jump_buttons: 'Show floating Start and End buttons while reading long session histories.',
+
+    settings_label_session_endless_scroll: 'Загружать старые сообщения при прокрутке вверх',
+
+    settings_desc_session_endless_scroll: 'Если включено, старые сообщения загружаются автоматически при прокрутке вверх. Если выключено, используйте кнопку загрузки старых сообщений.',
    open_in_browser: 'Открыть в браузере',
    settings_section_system_title: 'System',
    settings_tab_appearance: 'Appearance',
@@ -3006,6 +3057,13 @@ const LOCALES = {
  },

  es: {
+    offline_title: 'Conexión perdida',
+    offline_browser_detail: 'Tu navegador indica que este dispositivo está sin conexión.',
+    offline_network_detail: 'Hermes no está disponible desde este navegador ahora mismo.',
+    offline_autorefresh: 'Actualizaré esta página automáticamente cuando Hermes vuelva a estar disponible.',
+    offline_check_now: 'Comprobar ahora',
+    offline_checking: 'Comprobando…',
+    offline_stream_waiting: 'Conexión perdida. Esperando para actualizar…',
    _lang: 'es',
    _label: 'Español',
    _speech: 'es-ES',
@@ -3102,6 +3160,10 @@ const LOCALES = {
    untitled: 'Sin título',
    n_messages: (n) => `${n} mensajes`,
    load_older_messages: '↑ Desplázate hacia arriba o haz clic para cargar mensajes anteriores',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    queued_label: 'Enviar después de la respuesta',
    queued_count: (n) => n === 1 ? '1 en cola' : `${n} en cola`,
    queued_cancel: 'Cancelar mensaje en cola',
@@ -3823,6 +3885,12 @@ const LOCALES = {
    settings_update_check_failed: 'Error al comprobar actualizaciones',
    settings_label_workspace_panel_open: 'Mantener panel de espacio abierto',
    settings_desc_workspace_panel_open: 'Al activar, el panel de archivos se abre automáticamente en cada nueva sesión. Aún puedes cerrarlo manualmente.',
+    settings_label_session_jump_buttons: 'Show session jump buttons',
+    settings_desc_session_jump_buttons: 'Show floating Start and End buttons while reading long session histories.',
+
+    settings_label_session_endless_scroll: 'Cargar mensajes antiguos al desplazarse hacia arriba',
+
+    settings_desc_session_endless_scroll: 'Si está activado, los mensajes antiguos se cargan automáticamente al desplazarte hacia arriba. Si está desactivado, usa el botón de mensajes antiguos.',
    open_in_browser: 'Abrir en el navegador',
    settings_section_system_title: 'System',
    settings_tab_appearance: 'Appearance',
@@ -3959,6 +4027,13 @@ const LOCALES = {
  },

  de: {
+    offline_title: 'Verbindung verloren',
+    offline_browser_detail: 'Dein Browser meldet, dass dieses Gerät offline ist.',
+    offline_network_detail: 'Hermes ist von diesem Browser aus gerade nicht erreichbar.',
+    offline_autorefresh: 'Ich aktualisiere diese Seite automatisch, sobald Hermes wieder erreichbar ist.',
+    offline_check_now: 'Jetzt prüfen',
+    offline_checking: 'Prüfe…',
+    offline_stream_waiting: 'Verbindung verloren. Warte auf Aktualisierung…',
    _lang: 'de',
    _label: 'Deutsch',
    _speech: 'de-DE',
@@ -4055,6 +4130,10 @@ const LOCALES = {
    untitled: 'Unbenannt',
    n_messages: (n) => `${n} Nachrichten`,
    load_older_messages: '↑ Nach oben scrollen oder klicken, um ältere Nachrichten zu laden',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    queued_label: 'Wird nach Antwort gesendet',
    queued_count: (n) => n === 1 ? '1 in Warteschlange' : `${n} in Warteschlange`,
    queued_cancel: 'Nachricht abbrechen',
@@ -4511,6 +4590,12 @@ const LOCALES = {
    settings_update_check_failed: 'Update-Prüfung fehlgeschlagen',
    settings_label_workspace_panel_open: 'Arbeitsbereich-Panel standardmäßig öffnen',
    settings_desc_workspace_panel_open: 'Wenn aktiviert, wird der Datei-Browser bei jeder neuen Sitzung automatisch geöffnet. Er kann jederzeit manuell geschlossen werden.',
+    settings_label_session_jump_buttons: 'Show session jump buttons',
+    settings_desc_session_jump_buttons: 'Show floating Start and End buttons while reading long session histories.',
+
+    settings_label_session_endless_scroll: 'Ältere Nachrichten beim Hochscrollen laden',
+
+    settings_desc_session_endless_scroll: 'Wenn aktiviert, werden ältere Nachrichten beim Hochscrollen automatisch geladen. Wenn deaktiviert, nutzt du den Button für ältere Nachrichten.',

    workspace_drag_hint: 'Ziehen zum Neuordnen',
    workspace_reorder_failed: 'Neuordnen fehlgeschlagen',
@@ -4916,6 +5001,13 @@ const LOCALES = {
  },

  zh: {
+    offline_title: '连接已断开',
+    offline_browser_detail: '浏览器报告此设备当前离线。',
+    offline_network_detail: '此浏览器当前无法连接到 Hermes。',
+    offline_autorefresh: '当 Hermes 可访问时，我会自动刷新此页面。',
+    offline_check_now: '立即检查',
+    offline_checking: '正在检查…',
+    offline_stream_waiting: '连接已断开。正在等待刷新…',
    _lang: 'zh',
    _label: '\u7b80\u4f53\u4e2d\u6587',
    _speech: 'zh-CN',
@@ -5012,6 +5104,10 @@ const LOCALES = {
    untitled: '\u672a\u547d\u540d',
    n_messages: (n) => `${n} \u6761\u6d88\u606f`,
    load_older_messages: '↑ 向上滚动或点击加载更早的消息',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    queued_label: '响应后发送',
    queued_count: (n) => n === 1 ? '1 条排队' : `${n} 条排队`,
    queued_cancel: '取消排队消息',
@@ -5730,6 +5826,12 @@ const LOCALES = {
    settings_update_check_failed: '更新检查失败',
    settings_label_workspace_panel_open: '默认保持工作区面板打开',
    settings_desc_workspace_panel_open: '启用后，工作区/文件浏览器面板会在每次新会话时自动打开。您仍可随时手动关闭。',
+    settings_label_session_jump_buttons: 'Show session jump buttons',
+    settings_desc_session_jump_buttons: 'Show floating Start and End buttons while reading long session histories.',
+
+    settings_label_session_endless_scroll: '向上滚动时加载更早的消息',
+
+    settings_desc_session_endless_scroll: '启用后，向上滚动时会自动加载更早的消息。禁用时请使用加载更早消息按钮。',
    open_in_browser: '在浏览器中打开',
    settings_section_system_title: 'System',
    settings_tab_appearance: 'Appearance',
@@ -5964,6 +6066,10 @@ const LOCALES = {
    untitled: '\u672a\u547d\u540d',
    n_messages: (n) => `${n} \u689d\u8a0a\u606f`,
    load_older_messages: '↑ 向上捲動或點擊以載入較早的訊息',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    model_unavailable: '\uff08\u4e0d\u53ef\u7528\uff09',
    model_unavailable_title: '\u6b64\u6a21\u578b\u5df2\u7d93\u4e0d\u5728\u7576\u524d provider \u5217\u8868\u4e2d',
    provider_mismatch_warning: (m,p)=>`\"${m}\" \u53ef\u80fd\u7121\u6cd5\u5728\u7576\u524d\u914d\u7f6e\u7684\u63d0\u4f9b\u8005 (${p}) \u4e0b\u904b\u4f5c\u3002\u5c1a\u9001\uff0c\u6216\u5728\u7d42\u7aef\u57f7\u884c \`hermes model\` \u5207\u63db\u3002`,
@@ -6136,6 +6242,12 @@ const LOCALES = {
    settings_update_check_failed: '更新檢查失敗',
    settings_label_workspace_panel_open: '預設保持工作區面板開啓',
    settings_desc_workspace_panel_open: '啟用後，工作區/檔案瀏覽器面板會在每次新會話時自動開啓。您仍可隨時手動關閉。',
+    settings_label_session_jump_buttons: 'Show session jump buttons',
+    settings_desc_session_jump_buttons: 'Show floating Start and End buttons while reading long session histories.',
+
+    settings_label_session_endless_scroll: '向上捲動時載入較早訊息',
+
+    settings_desc_session_endless_scroll: '啟用後，向上捲動時會自動載入較早訊息。停用時請使用載入較早訊息按鈕。',
    open_in_browser: '在瀏覽器中開啓',
    settings_dropdown_conversation: '對話',
    settings_dropdown_appearance: '外觀',
@@ -6288,6 +6400,10 @@ const LOCALES = {
    downloading: (filename) => `正在下載 ${filename}…`,
    n_messages: (n) => `${n} 則訊息`,
    load_older_messages: '↑ 向上捲動或點擊以載入較早的訊息',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    onboarding_api_key_help_prefix: '\u900f\u904e\u4ee5\u4e0b\u65b9\u5f0f\u5132\u5b58\u70ba Hermes .env \u6a94\u6848\u4e2d\u7684\u6a5f\u5bc6',
    onboarding_api_key_label: 'API \u91d1\u9470',
    onboarding_api_key_placeholder: '\u7559\u7a7a\u4ee5\u4fdd\u7559\u5df2\u5132\u5b58\u7684\u91d1\u9470',
@@ -6857,6 +6973,13 @@ const LOCALES = {
  },

  pt: {
+    offline_title: 'Conexão perdida',
+    offline_browser_detail: 'O navegador informa que este dispositivo está offline.',
+    offline_network_detail: 'O Hermes está inacessível neste navegador agora.',
+    offline_autorefresh: 'Vou atualizar esta página automaticamente quando o Hermes voltar a responder.',
+    offline_check_now: 'Verificar agora',
+    offline_checking: 'Verificando…',
+    offline_stream_waiting: 'Conexão perdida. Aguardando para atualizar…',
    _lang: 'pt',
    _label: 'Português',
    _speech: 'pt-BR',
@@ -6906,6 +7029,10 @@ const LOCALES = {
    untitled: 'Sem título',
    n_messages: (n) => `${n} mensagens`,
    load_older_messages: '↑ Role para cima ou clique para carregar mensagens mais antigas',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    queued_label: 'Envia após a resposta',
    queued_count: (n) => n === 1 ? '1 na fila' : `${n} na fila`,
    queued_cancel: 'Cancelar mensagem na fila',
@@ -7170,6 +7297,12 @@ const LOCALES = {
    settings_update_check_failed: 'Falha ao verificar updates',
    settings_label_workspace_panel_open: 'Manter painel workspace aberto por padrão',
    settings_desc_workspace_panel_open: 'Quando ativo, o painel workspace abre automaticamente com cada nova sessão.',
+    settings_label_session_jump_buttons: 'Show session jump buttons',
+    settings_desc_session_jump_buttons: 'Show floating Start and End buttons while reading long session histories.',
+
+    settings_label_session_endless_scroll: 'Carregar mensagens antigas ao rolar para cima',
+
+    settings_desc_session_endless_scroll: 'Quando ativado, mensagens antigas carregam automaticamente ao rolar para cima. Quando desativado, use o botão de mensagens antigas.',
    open_in_browser: 'Abrir no navegador',
    settings_dropdown_conversation: 'Conversa',
    settings_dropdown_appearance: 'Aparência',
@@ -7706,6 +7839,13 @@ const LOCALES = {
    disable_auth_confirm_title: 'Desativar proteção por senha',
  },
  ko: {
+    offline_title: '연결이 끊겼습니다',
+    offline_browser_detail: '브라우저가 이 장치가 오프라인이라고 보고합니다.',
+    offline_network_detail: '현재 이 브라우저에서 Hermes에 연결할 수 없습니다.',
+    offline_autorefresh: 'Hermes에 다시 연결되면 이 페이지를 자동으로 새로고침합니다.',
+    offline_check_now: '지금 확인',
+    offline_checking: '확인 중…',
+    offline_stream_waiting: '연결이 끊겼습니다. 새로고침을 기다리는 중…',
    _lang: 'ko',
    _label: '한국어',
    _speech: 'ko-KR',
@@ -7802,6 +7942,10 @@ const LOCALES = {
    untitled: '제목 없음',
    n_messages: (n) => `${n}개 메시지`,
    load_older_messages: '↑ 위로 스크롤하거나 클릭하여 이전 메시지 불러오기',
+    session_jump_start: 'Start',
+    session_jump_start_label: 'Jump to beginning of session',
+    session_jump_end: 'End',
+    session_jump_end_label: 'Jump to end of session',
    queued_label: 'Sends after response',
    queued_count: (n) => n === 1 ? '1 queued' : `${n} queued`,
    queued_cancel: 'Cancel queued message',
@@ -8089,6 +8233,12 @@ const LOCALES = {
    settings_update_check_failed: 'Update check failed',
    settings_label_workspace_panel_open: '기본으로 워크스페이스 패널 열기',
    settings_desc_workspace_panel_open: '활성화하면 새 세션마다 워크스페이스/파일 브라우저 패널이 자동으로 열립니다. 언제든지 수동으로 닫을 수 있습니다.',
+    settings_label_session_jump_buttons: 'Show session jump buttons',
+    settings_desc_session_jump_buttons: 'Show floating Start and End buttons while reading long session histories.',
+
+    settings_label_session_endless_scroll: '위로 스크롤할 때 이전 메시지 불러오기',
+
+    settings_desc_session_endless_scroll: '활성화하면 위로 스크롤할 때 이전 메시지를 자동으로 불러옵니다. 비활성화하면 이전 메시지 버튼을 사용합니다.',
    open_in_browser: '브라우저에서 열기',
    settings_dropdown_conversation: '대화',
    settings_dropdown_appearance: '외형',
@@ -8832,6 +8982,11 @@ function applyLocaleToDOM() {
    const val = t(key);
    if (val && val !== key) el.placeholder = val;
  });
+  document.querySelectorAll('[data-i18n-aria-label]').forEach(el => {
+    const key = el.getAttribute('data-i18n-aria-label');
+    const val = t(key);
+    if (val && val !== key) el.setAttribute('aria-label', val);
+  });
  if (typeof syncAppTitlebar === 'function') syncAppTitlebar();
 }

@@ -21,7 +21,7 @@
 <meta name="theme-color" content="#FEFCF7" media="(prefers-color-scheme: light)">
 <meta name="theme-color" content="#0D0D1A" media="(prefers-color-scheme: dark)">
 <meta name="theme-color" id="hermes-theme-color" content="#0D0D1A">
-<script>(function(){try{var t=localStorage.getItem('hermes-theme')||'dark';if(t==='system')t=window.matchMedia('(prefers-color-scheme:dark)').matches?'dark':'light';var c=t==='dark'?'#0D0D1A':'#FEFCF7';var m=document.getElementById('hermes-theme-color');if(m)m.setAttribute('content',c);}catch(e){}})()</script>
+<script>(function(){try{var t=localStorage.getItem('hermes-theme')||'dark';if(t==='system')t=window.matchMedia('(prefers-color-scheme:dark)').matches?'dark':'light';var c=t==='dark'?'#0D0D1A':'#FEFCF7';document.querySelectorAll('meta[name="theme-color"]').forEach(function(m){m.setAttribute('content',c);m.removeAttribute('media');});}catch(e){}})()</script>
 <script>(function(){try{document.documentElement.dataset.workspacePanel=localStorage.getItem('hermes-webui-workspace-panel')==='open'?'open':'closed';}catch(e){document.documentElement.dataset.workspacePanel='closed';}})()</script>
 <link rel="stylesheet" href="static/style.css?v=__WEBUI_VERSION__">
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/xterm@5.3.0/css/xterm.css" integrity="sha384-LJcOxlx9IMbNXDqJ2axpfEQKkAYbFjJfhXexLfiRJhjDU81mzgkiQq8rkV0j6dVh" crossorigin="anonymous">
@@ -297,7 +297,8 @@
  <main class="main">
    <div id="mainChat" class="main-view">
    <div class="messages" id="messages">
-      <button id="scrollToBottomBtn" class="scroll-to-bottom-btn" aria-label="Scroll to bottom" onclick="scrollToBottom()" style="display:none">↓</button>
+      <button id="jumpToSessionStartBtn" class="session-jump-btn session-jump-btn--start" aria-label="Jump to beginning of session" data-i18n-aria-label="session_jump_start_label" data-i18n-title="session_jump_start_label" onclick="jumpToSessionStart()" style="display:none"><span aria-hidden="true">↑</span><span data-i18n="session_jump_start">Start</span></button>
+      <button id="scrollToBottomBtn" class="scroll-to-bottom-btn" style="display:none" onclick="scrollToBottom()" aria-label="Scroll to bottom" data-i18n-aria-label="session_jump_end_label" data-i18n-title="session_jump_end_label"><span aria-hidden="true">↓</span><span class="session-jump-btn__text" data-i18n="session_jump_end">End</span></button>
      <div class="empty-state" id="emptyState">
        <div class="empty-logo"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64" width="80" height="80" aria-label="Hermes caduceus">
          <defs>
@@ -347,6 +348,14 @@
        <button class="reconnect-btn" onclick="refreshSession()"><svg width="13" height="13" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true" style="vertical-align:-1px"><polyline points="23 4 23 10 17 10"/><polyline points="1 20 1 14 7 14"/><path d="M3.51 9a9 9 0 0 1 14.85-3.36L23 10M1 14l4.64 4.36A9 9 0 0 0 20.49 15"/></svg> Reload</button>
      </div>
    </div>
+    <div class="offline-banner" id="offlineBanner" role="status" aria-live="assertive" hidden>
+      <div class="offline-copy">
+        <strong id="offlineTitle" data-i18n="offline_title">Connection lost</strong>
+        <span id="offlineDetails" data-i18n="offline_browser_detail">Your browser reports that this device is offline.</span>
+        <span id="offlineAutorefresh" data-i18n="offline_autorefresh">I will refresh this page automatically when Hermes is reachable again.</span>
+      </div>
+      <button class="offline-action" id="offlineCheckNow" type="button" onclick="checkOfflineRecoveryNow()" data-i18n="offline_check_now">Check now</button>
+    </div>
    <div class="agent-health-banner" id="agentHealthBanner" role="alert" aria-live="assertive" hidden>
      <div class="agent-health-copy">
        <strong id="agentHealthTitle">Hermes agent is not responding</strong>
@@ -863,6 +872,17 @@
              </label>
              <div style="font-size:11px;color:var(--muted);margin-top:4px" data-i18n="settings_desc_workspace_panel_open">When enabled, the workspace / file browser panel opens automatically with each new session. You can still close it manually at any time.</div>
            </div>
+            <div class="settings-field">
+              <label style="display:flex;align-items:center;gap:8px;cursor:pointer">
+                <input type="checkbox" id="settingsSessionJumpButtons" style="width:15px;height:15px;accent-color:var(--accent)">
+                <span data-i18n="settings_label_session_jump_buttons">Show session jump buttons</span>
+              </label>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px" data-i18n="settings_desc_session_jump_buttons">Show floating Start and End buttons while reading long session histories.</div>
+                <input type="checkbox" id="settingsSessionEndlessScroll" style="width:15px;height:15px;accent-color:var(--accent)">
+                <span data-i18n="settings_label_session_endless_scroll">Load older messages while scrolling up</span>
+              </label>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px" data-i18n="settings_desc_session_endless_scroll">When enabled, older messages load automatically as you scroll upward. When disabled, use the older-messages button.</div>
+            </div>
            <div id="settingsAppearanceAutosaveStatus" class="settings-autosave-status" aria-live="polite"></div>
          </div>
          <div class="settings-pane" id="settingsPanePreferences">
@@ -4,8 +4,8 @@
  "description": "Hermes AI Agent Web UI",
  "start_url": "./",
  "display": "standalone",
-  "background_color": "#1a1a1a",
-  "theme_color": "#1a1a1a",
+  "background_color": "#0D0D1A",
+  "theme_color": "#0D0D1A",
  "orientation": "portrait-primary",
  "icons": [
    {
@@ -32,6 +32,19 @@ function _markActiveSessionViewedOnReturn() {
  if(typeof renderSessionListFromCache==='function') renderSessionListFromCache();
 }

+function _deferStreamErrorIfOffline(){
+  if(typeof isOfflineBannerVisible==='function' && isOfflineBannerVisible()){
+    setComposerStatus(t('offline_stream_waiting'));
+    return true;
+  }
+  if(typeof showOfflineBanner==='function' && navigator.onLine===false){
+    showOfflineBanner('browser');
+    setComposerStatus(t('offline_stream_waiting'));
+    return true;
+  }
+  return false;
+}
+
 document.addEventListener('visibilitychange', _markActiveSessionViewedOnReturn);
 window.addEventListener('focus', _markActiveSessionViewedOnReturn);
 // TTS: pause speech synthesis when user focuses the composer (#499)
@@ -1207,6 +1220,7 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){

    source.addEventListener('error',async e=>{
      source.close();
+      if(_deferStreamErrorIfOffline()) return;
      if(_terminalStateReached || _streamFinalized){
        _closeSource();
        return;
@@ -1223,13 +1237,17 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
              _wireSSE(new EventSource(new URL(`api/chat/stream?stream_id=${encodeURIComponent(streamId)}`,document.baseURI||location.href).href,{withCredentials:true}));
              return;
            }
-          }catch(_){}
+          }catch(_){
+            if(_deferStreamErrorIfOffline()) return;
+          }
          if(await _restoreSettledSession()) return;
+          if(_deferStreamErrorIfOffline()) return;
          _handleStreamError();
        },1500);
        return;
      }
      if(await _restoreSettledSession()) return;
+      if(_deferStreamErrorIfOffline()) return;
      _handleStreamError();
    });

@@ -4251,6 +4251,8 @@ function _appearancePayloadFromUi(){
    theme: ($('settingsTheme')||{}).value || localStorage.getItem('hermes-theme') || 'dark',
    skin: ($('settingsSkin')||{}).value || localStorage.getItem('hermes-skin') || 'default',
    font_size: ($('settingsFontSize')||{}).value || localStorage.getItem('hermes-font-size') || 'default',
+    session_jump_buttons: !!($('settingsSessionJumpButtons')||{}).checked,
+    session_endless_scroll: !!($('settingsSessionEndlessScroll')||{}).checked,
  };
 }

@@ -4298,6 +4300,11 @@ async function _autosaveAppearanceSettings(payload){
    if(saved&&saved.font_size){
      localStorage.setItem('hermes-font-size',saved.font_size);
    }
+    if(saved){
+      window._sessionJumpButtonsEnabled=!!saved.session_jump_buttons;
+      if(typeof _applySessionNavigationPrefs==='function') _applySessionNavigationPrefs();
+    }
+    window._sessionEndlessScrollEnabled=!!(saved&&saved.session_endless_scroll);
    _setAppearanceAutosaveStatus('saved');
  }catch(e){
    console.warn('[settings] appearance autosave failed', e);
@@ -4454,6 +4461,17 @@ async function loadSettingsPanel(){
    const fontSizeSel=$('settingsFontSize');
    if(fontSizeSel) fontSizeSel.value=fontSizeVal;
    if(typeof _syncFontSizePicker==='function') _syncFontSizePicker(fontSizeVal);
+    const jumpButtonsCb=$('settingsSessionJumpButtons');
+    if(jumpButtonsCb){
+      jumpButtonsCb.checked=!!settings.session_jump_buttons;
+      window._sessionJumpButtonsEnabled=jumpButtonsCb.checked;
+      jumpButtonsCb.onchange=function(){
+        window._sessionJumpButtonsEnabled=this.checked;
+        if(typeof _applySessionNavigationPrefs==='function') _applySessionNavigationPrefs();
+        _scheduleAppearanceAutosave();
+      };
+    }
+    if(typeof _applySessionNavigationPrefs==='function') _applySessionNavigationPrefs();
    // Workspace panel default-open toggle (localStorage-backed)
    // Uses a separate key (hermes-webui-workspace-panel-pref) so that
    // closing the panel via toolbar X does not clear the user's preference.
@@ -4470,6 +4488,15 @@ async function loadSettingsPanel(){
        else if(!open&&_workspacePanelMode!=='closed') toggleWorkspacePanel(false);
      };
    }
+    const endlessScrollCb=$('settingsSessionEndlessScroll');
+    if(endlessScrollCb){
+      endlessScrollCb.checked=!!settings.session_endless_scroll;
+      window._sessionEndlessScrollEnabled=endlessScrollCb.checked;
+      endlessScrollCb.onchange=function(){
+        window._sessionEndlessScrollEnabled=this.checked;
+        _scheduleAppearanceAutosave();
+      };
+    }
    const resolvedLanguage=(typeof resolvePreferredLocale==='function')
      ? resolvePreferredLocale(settings.language, localStorage.getItem('hermes-lang'))
      : (settings.language || localStorage.getItem('hermes-lang') || 'en');
@@ -5124,8 +5151,11 @@ function _applySavedSettingsUi(saved, body, opts){
  window._notificationsEnabled=body.notifications_enabled;
  window._showThinking=body.show_thinking!==false;
  window._simplifiedToolCalling=body.simplified_tool_calling!==false;
+  window._sessionJumpButtonsEnabled=!!body.session_jump_buttons;
+  if(typeof _applySessionNavigationPrefs==='function') _applySessionNavigationPrefs();
  window._sidebarDensity=sidebarDensity==='detailed'?'detailed':'compact';
  window._busyInputMode=body.busy_input_mode||'queue';
+  window._sessionEndlessScrollEnabled=!!body.session_endless_scroll;
  window._botName=body.bot_name||'Hermes';
  if(typeof applyBotName==='function') applyBotName();
  if(typeof setLocale==='function') setLocale(language);
@@ -5221,6 +5251,8 @@ async function saveSettings(andClose){
  body.theme=theme;
  body.skin=skin;
  body.font_size=fontSize;
+  body.session_jump_buttons=!!($('settingsSessionJumpButtons')||{}).checked;
+  body.session_endless_scroll=!!($('settingsSessionEndlessScroll')||{}).checked;
  body.language=language;
  body.show_token_usage=showTokenUsage;
  body.show_tps=showTps;
@@ -536,6 +536,14 @@
  .reconnect-banner.visible{display:flex;}
  .reconnect-btn{padding:6px 12px;border-radius:8px;font-size:12px;font-weight:600;background:var(--accent-bg-strong);border:1px solid var(--accent-bg-strong);color:var(--accent-text);cursor:pointer;}
  .reconnect-btn:hover{background:var(--accent-bg-strong);}
+  .offline-banner{position:fixed;left:0;right:0;top:0;z-index:1200;display:none;align-items:center;justify-content:space-between;gap:14px;padding:12px 18px;border-bottom:1px solid color-mix(in srgb,var(--warning,#f6c343) 55%,var(--surface));background:color-mix(in srgb,var(--bg-1,#0d0d1a) 88%,var(--warning,#f6c343));color:var(--text);box-shadow:0 12px 40px rgba(0,0,0,.22);backdrop-filter:blur(10px);}
+  .offline-banner.visible{display:flex;}
+  .offline-copy{display:flex;flex-direction:column;gap:3px;min-width:0;font-size:13px;line-height:1.35;}
+  .offline-copy strong{color:var(--warning,#f6c343);font-size:13px;letter-spacing:.08em;text-transform:uppercase;}
+  .offline-copy span{color:var(--muted);}
+  .offline-action{flex-shrink:0;padding:7px 13px;border-radius:9px;border:1px solid color-mix(in srgb,var(--warning,#f6c343) 48%,var(--surface));background:color-mix(in srgb,var(--warning,#f6c343) 12%,var(--surface));color:var(--warning,#f6c343);font-size:12px;font-weight:700;cursor:pointer;}
+  .offline-action:hover{background:color-mix(in srgb,var(--warning,#f6c343) 20%,var(--surface));}
+  .offline-action[disabled]{cursor:wait;opacity:.65;}
  .agent-health-banner{position:sticky;bottom:0;z-index:4;display:none;align-items:center;justify-content:space-between;gap:12px;margin:10px auto 0;max-width:var(--msg-max);width:calc(100% - 40px);padding:12px 16px;border:1px solid color-mix(in srgb,var(--error) 55%,var(--surface));border-radius:12px;background:color-mix(in srgb,var(--error) 14%,var(--surface));color:var(--text);box-shadow:0 10px 32px rgba(0,0,0,.16);}
  .agent-health-banner.visible{display:flex;}
  .agent-health-copy{display:flex;flex-direction:column;gap:3px;min-width:0;font-size:13px;line-height:1.35;}
@@ -772,9 +780,16 @@
  .workspace-toggle-btn:disabled{opacity:.38;cursor:not-allowed;}
  .chip.model{color:var(--accent-text);border-color:var(--accent-bg-strong);background:var(--accent-bg);}
  .messages{flex:1;overflow-y:auto;display:flex;flex-direction:column;min-height:0;position:relative;z-index:0;-webkit-overflow-scrolling:touch;touch-action:pan-y;overscroll-behavior-y:contain;overflow-anchor:none;}
-  /* sticky-first-child: button is first child of .messages so its natural position is above viewport; sticky+bottom:16px pins it there when visible */
-  .scroll-to-bottom-btn{position:sticky;bottom:16px;align-self:flex-end;margin-right:20px;width:32px;height:32px;border-radius:50%;border:1px solid var(--border2);background:var(--code-bg);color:var(--muted);font-size:16px;cursor:pointer;display:flex;align-items:center;justify-content:center;box-shadow:0 2px 8px rgba(0,0,0,.25);z-index:10;transition:color .12s,border-color .12s,background .12s;}
+  /* sticky-first-child: button is early in .messages so its natural position is above viewport; sticky+bottom pins it there when visible */
+  .scroll-to-bottom-btn{position:sticky;bottom:16px;align-self:flex-end;margin-right:20px;width:32px;height:32px;border-radius:50%;border:1px solid var(--border2);background:var(--code-bg);color:var(--muted);font-size:16px;cursor:pointer;display:flex;align-items:center;justify-content:center;box-shadow:0 2px 8px rgba(0,0,0,.25);z-index:10;transition:color .12s,border-color .12s,background .12s,transform .12s;}
  .scroll-to-bottom-btn:hover{color:var(--text);border-color:var(--border);background:var(--hover-bg);}
+  .session-jump-btn__text{display:none;}
+  .session-jump-btn{position:sticky;align-self:flex-end;flex:0 0 32px;min-height:32px;margin-right:20px;height:32px;border-radius:999px;border:1px solid var(--border2);background:var(--code-bg);color:var(--muted);font-size:12px;font-weight:600;cursor:pointer;display:flex;align-items:center;justify-content:center;gap:5px;padding:0 11px;box-shadow:0 2px 8px rgba(0,0,0,.25);z-index:11;transition:color .12s,border-color .12s,background .12s,opacity .12s,transform .12s;}
+  .session-jump-btn:hover{color:var(--text);border-color:var(--border);background:var(--hover-bg);transform:translateY(-1px);}
+  .session-jump-btn--start{top:16px;margin-bottom:-36px;}
+  .messages.session-nav-enabled .scroll-to-bottom-btn{width:auto;min-width:32px;border-radius:999px;font-size:12px;font-weight:600;gap:5px;padding:0 11px;}
+  .messages.session-nav-enabled .scroll-to-bottom-btn:hover{transform:translateY(-1px);}
+  .messages.session-nav-enabled .session-jump-btn__text{display:inline;}
  .messages-inner{margin:0 auto;width:100%;padding:20px 24px 32px;display:flex;flex-direction:column;}
  @media(min-width:1400px){.messages-inner{max-width:1100px;}}
  @media(min-width:1800px){.messages-inner{max-width:1200px;}}
@@ -68,7 +68,7 @@ self.addEventListener('activate', (event) => {
 // - API calls (/api/*, /stream) → always network (never cache)
 // - Login assets → always network (never cache stale auth code)
 // - Page navigations → network-first so auth redirects/cookies are honored
-// - Shell assets → cache-first with network fallback
+// - Shell assets → network-first with cache fallback
 // - Everything else → network-only
 self.addEventListener('fetch', (event) => {
  const url = new URL(event.request.url);
@@ -131,7 +131,7 @@ self.addEventListener('fetch', (event) => {
    return;
  }

-  // Only explicit shell assets use cache-first. Everything else should hit the
+  // Only explicit shell assets are cached. Everything else should hit the
  // network so stale one-off files (especially auth/login scripts) do not get
  // trapped in CacheStorage until a manual cache clear.
  const scopePath = new URL(self.registration.scope).pathname;
@@ -141,21 +141,22 @@ self.addEventListener('fetch', (event) => {
  const shellPath = './' + relPath.replace(/^\/+/, '') + url.search;
  if (!SHELL_ASSETS.includes(shellPath)) return;

-  // Shell assets: cache-first
+  // Shell assets: network-first with cache fallback. This keeps offline support
+  // but avoids executing stale JS/CSS after a local hotfix when WEBUI_VERSION
+  // has not changed yet (e.g. before a guarded restart updates the ?v token).
  event.respondWith(
-    caches.match(event.request).then((cached) => {
-      if (cached) return cached;
-      return fetch(event.request).then((response) => {
-        // Cache successful GET responses for shell assets
-        if (
-          event.request.method === 'GET' &&
-          response.status === 200
-        ) {
-          const clone = response.clone();
-          caches.open(CACHE_NAME).then((cache) => cache.put(event.request, clone));
-        }
-        return response;
-      });
-    })
+    fetch(event.request).then((response) => {
+      if (
+        event.request.method === 'GET' &&
+        response.status === 200
+      ) {
+        const clone = response.clone();
+        caches.open(CACHE_NAME).then((cache) => cache.put(event.request, clone));
+      }
+      return response;
+    }).catch(() => caches.match(event.request).then((cached) => cached || new Response('Offline', {
+      status: 503,
+      headers: { 'Content-Type': 'text/plain; charset=utf-8' },
+    })))
  );
 });
@@ -11,6 +11,105 @@ const MAX_UPLOAD_MB=Math.round(MAX_UPLOAD_BYTES/1024/1024);
 // single-threaded so only one done event fires at a time in practice.
 let _queueDrainSid=null;
 const $=id=>document.getElementById(id);
+const OFFLINE_RECHECK_MS=2500;
+let _offlineVisible=false;
+let _offlineReason='browser';
+let _offlineProbeTimer=null;
+let _offlineChecking=false;
+let _offlineProbePromise=null;
+let _offlineHealthProbePromise=null;
+let _offlineRawFetch=null;
+let _offlineFetchPatched=false;
+function _browserReportsOnline(){return !('onLine' in navigator)||navigator.onLine!==false;}
+function _offlineHealthUrl(){const url=new URL('health',document.baseURI||location.href);url.searchParams.set('offline_probe',String(Date.now()));return url.href;}
+function _setOfflineChecking(checking){
+  _offlineChecking=!!checking;
+  const btn=$('offlineCheckNow');
+  if(btn){btn.disabled=_offlineChecking;btn.textContent=_offlineChecking?t('offline_checking'):t('offline_check_now');}
+}
+function _renderOfflineBanner(){
+  const banner=$('offlineBanner');
+  if(!banner)return;
+  const detail=$('offlineDetails');
+  if(detail)detail.textContent=t(_offlineReason==='browser'?'offline_browser_detail':'offline_network_detail');
+  const title=$('offlineTitle');
+  if(title)title.textContent=t('offline_title');
+  const auto=$('offlineAutorefresh');
+  if(auto)auto.textContent=t('offline_autorefresh');
+  _setOfflineChecking(_offlineChecking);
+  banner.hidden=false;
+  banner.classList.add('visible');
+}
+function _startOfflineProbeTimer(){
+  if(_offlineProbeTimer)return;
+  _offlineProbeTimer=setInterval(()=>{checkOfflineRecoveryNow();},OFFLINE_RECHECK_MS);
+}
+function _stopOfflineProbeTimer(){
+  if(_offlineProbeTimer){clearInterval(_offlineProbeTimer);_offlineProbeTimer=null;}
+}
+function showOfflineBanner(reason){
+  _offlineVisible=true;
+  _offlineReason=reason||(_browserReportsOnline()?'network':'browser');
+  _renderOfflineBanner();
+  _startOfflineProbeTimer();
+}
+function isOfflineBannerVisible(){return _offlineVisible;}
+function _hideOfflineBanner(){
+  _offlineVisible=false;
+  _stopOfflineProbeTimer();
+  _setOfflineChecking(false);
+  const banner=$('offlineBanner');
+  if(banner){banner.classList.remove('visible');banner.hidden=true;}
+}
+async function _probeOfflineRecovery(){
+  if(_offlineHealthProbePromise)return _offlineHealthProbePromise;
+  _offlineHealthProbePromise=(async()=>{
+    const fetcher=_offlineRawFetch||window.fetch.bind(window);
+    try{
+      const res=await fetcher(_offlineHealthUrl(),{cache:'no-store',credentials:'include'});
+      return !!(res&&res.ok);
+    }catch(_){return false;}
+  })();
+  try{return await _offlineHealthProbePromise;}
+  finally{_offlineHealthProbePromise=null;}
+}
+async function checkOfflineRecoveryNow(){
+  if(_offlineProbePromise)return _offlineProbePromise;
+  _offlineProbePromise=(async()=>{
+    if(!_offlineVisible)return false;
+    if(!_browserReportsOnline()){showOfflineBanner('browser');return false;}
+    _setOfflineChecking(true);
+    const ok=await _probeOfflineRecovery();
+    _setOfflineChecking(false);
+    if(ok){_stopOfflineProbeTimer();window.location.reload();return true;}
+    showOfflineBanner('network');
+    return false;
+  })();
+  try{return await _offlineProbePromise;}
+  finally{_offlineProbePromise=null;}
+}
+function _isAbortError(e){return !!(e&&(e.name==='AbortError'||e.code===20));}
+function _patchOfflineFetch(){
+  if(_offlineFetchPatched||typeof window.fetch!=='function')return;
+  _offlineFetchPatched=true;
+  _offlineRawFetch=window.fetch.bind(window);
+  window.fetch=async function(...args){
+    try{return await _offlineRawFetch(...args);}
+    catch(e){
+      if(!_browserReportsOnline())showOfflineBanner('browser');
+      else if(e instanceof TypeError&&!_isAbortError(e))void _probeOfflineRecovery().then(ok=>{if(!ok)showOfflineBanner('network');});
+      throw e;
+    }
+  };
+}
+function initOfflineMonitor(){
+  _patchOfflineFetch();
+  window.addEventListener('offline',()=>showOfflineBanner('browser'));
+  window.addEventListener('online',()=>{if(_offlineVisible)checkOfflineRecoveryNow();});
+  if(!_browserReportsOnline())showOfflineBanner('browser');
+}
+if(document.readyState==='loading')document.addEventListener('DOMContentLoaded',initOfflineMonitor,{once:true});
+else initOfflineMonitor();
 // Redirect to login when the server responds with 401 (auth session expired).
 // Handles iOS PWA standalone mode and keeps subpath mounts like /hermes/ from
 // escaping to the personal site root /login.
@@ -185,6 +284,9 @@ function _messageRenderableMessageCount(){
 function _messageHiddenBeforeCount(){
  return Math.max(0,_messageRenderableMessageCount()-_currentMessageRenderWindowSize());
 }
+function _isSessionEndlessScrollEnabled(){
+  return window._sessionEndlessScrollEnabled===true;
+}
 function _wireMessageWindowLoadEarlierButton(){
  const indicator=$('loadOlderIndicator');
  if(!indicator) return;
@@ -205,6 +307,48 @@ function _showEarlierRenderedMessages(){
  }
  _scrollPinned=false;
 }
+function _isSessionJumpButtonsEnabled(){
+  return window._sessionJumpButtonsEnabled===true;
+}
+function _applySessionNavigationPrefs(){
+  const container=$('messages');
+  if(container) container.classList.toggle('session-nav-enabled',_isSessionJumpButtonsEnabled());
+  _updateSessionStartJumpButton();
+}
+function _updateSessionStartJumpButton(){
+  const btn=$('jumpToSessionStartBtn');
+  const container=$('messages');
+  if(!btn||!container) return;
+  if(!_isSessionJumpButtonsEnabled()){
+    btn.style.display='none';
+    return;
+  }
+  const hasSession=!!(S&&S.session&&S.messages&&S.messages.length);
+  const awayFromStart=container.scrollTop>Math.max(240,container.clientHeight*0.35);
+  const hasScrollableHistory=container.scrollHeight>container.clientHeight+Math.max(240,container.clientHeight*0.35);
+  const canRevealStart=hasScrollableHistory||_messageHiddenBeforeCount()>0||!!(typeof _messagesTruncated!=='undefined'&&_messagesTruncated);
+  btn.style.display=(hasSession&&canRevealStart&&awayFromStart)?'flex':'none';
+}
+async function jumpToSessionStart(){
+  const container=$('messages');
+  if(!container||!S.session) return;
+  _scrollPinned=false;
+  _messageUserUnpinned=true;
+  _programmaticScroll=true;
+  try{
+    if(typeof _ensureAllMessagesLoaded==='function') await _ensureAllMessagesLoaded();
+    _messageRenderWindowSize=Math.max(_currentMessageRenderWindowSize(),_messageRenderableMessageCount());
+    renderMessages({ preserveScroll:true });
+    requestAnimationFrame(()=>{
+      container.scrollTop=0;
+      _updateSessionStartJumpButton();
+      requestAnimationFrame(()=>{ _programmaticScroll=false; });
+    });
+  }catch(e){
+    console.warn('jumpToSessionStart failed:',e);
+    _programmaticScroll=false;
+  }
+}

 const DASHBOARD_STATUS_TTL_MS=60000;
 let _dashboardStatusCache=null;
@@ -1574,8 +1718,12 @@ if (typeof window !== 'undefined') window._resetScrollDirectionTracker = _resetS
      } // #1360
      const btn=$('scrollToBottomBtn');
      if(btn) btn.style.display=_scrollPinned?'none':'flex';
-      // Load older messages when scrolled near the top
-      if(el.scrollTop<80 && typeof _messagesTruncated!=='undefined' && _messagesTruncated && typeof _loadOlderMessages==='function'){
+      if(typeof _updateSessionStartJumpButton==='function') _updateSessionStartJumpButton();
+      // Prefetch older messages before the reader hits the hard top. Prepending
+      // then preserving scrollTop is seamless only if there is runway left for
+      // the user's continued upward wheel/touch movement.
+      const olderPrefetchPx=Math.max(600,el.clientHeight*1.5);
+      if(_isSessionEndlessScrollEnabled()&&el.scrollTop<olderPrefetchPx && typeof _messagesTruncated!=='undefined' && _messagesTruncated && typeof _loadOlderMessages==='function'){
        _loadOlderMessages();
      }
    });
@@ -1913,6 +2061,7 @@ function scrollToBottom(){
  _settleMessageScrollToBottom(true);
  const btn=$('scrollToBottomBtn');
  if(btn) btn.style.display='none';
+  if(typeof _updateSessionStartJumpButton==='function') _updateSessionStartJumpButton();
 }

 function _fmtOllamaLabel(mid){
@@ -4566,6 +4715,7 @@ function renderMessages(options){
      inner.innerHTML=cached.html;
      _sessionHtmlCacheSid=sid;
      _wireMessageWindowLoadEarlierButton();
+      if(typeof _applySessionNavigationPrefs==='function') _applySessionNavigationPrefs();
      _scrollAfterMessageRender(preserveScroll);
      requestAnimationFrame(()=>{highlightCode();addCopyButtons();loadDiffInline();loadCsvInline();loadExcalidrawInline();loadPdfInline();loadHtmlInline();renderMermaidBlocks();renderKatexBlocks();});
      requestAnimationFrame(()=>{highlightCode();addCopyButtons();initTreeViews();loadPdfInline();loadHtmlInline();renderMermaidBlocks();renderKatexBlocks();});
@@ -4626,6 +4776,7 @@ function renderMessages(options){
  const renderVisWithIdx=visWithIdx.slice(windowStart);
  const firstRenderedRawIdx=renderVisWithIdx.length?renderVisWithIdx[0].rawIdx:Infinity;
  const hasServerOlder=!!(typeof _messagesTruncated!=='undefined' && _messagesTruncated && S.messages.length>0);
+  if(typeof _applySessionNavigationPrefs==='function') _applySessionNavigationPrefs();
  if(hiddenBeforeCount>0 || hasServerOlder){
    const indicator=document.createElement('button');
    indicator.type='button';
@@ -0,0 +1,72 @@
+"""Regression coverage for the browser-offline banner and auto-refresh loop."""
+
+from __future__ import annotations
+
+import pathlib
+
+
+REPO_ROOT = pathlib.Path(__file__).parent.parent
+UI_JS = (REPO_ROOT / "static" / "ui.js").read_text(encoding="utf-8")
+MESSAGES_JS = (REPO_ROOT / "static" / "messages.js").read_text(encoding="utf-8")
+INDEX_HTML = (REPO_ROOT / "static" / "index.html").read_text(encoding="utf-8")
+STYLE_CSS = (REPO_ROOT / "static" / "style.css").read_text(encoding="utf-8")
+I18N_JS = (REPO_ROOT / "static" / "i18n.js").read_text(encoding="utf-8")
+
+
+def test_offline_banner_markup_styles_and_copy_exist():
+    assert 'id="offlineBanner"' in INDEX_HTML
+    assert 'role="status"' in INDEX_HTML
+    assert 'aria-live="assertive"' in INDEX_HTML
+    assert 'onclick="checkOfflineRecoveryNow()"' in INDEX_HTML
+    assert ".offline-banner" in STYLE_CSS
+    assert ".offline-banner.visible" in STYLE_CSS
+    assert ".offline-action[disabled]" in STYLE_CSS
+    for key in (
+        "offline_title",
+        "offline_browser_detail",
+        "offline_network_detail",
+        "offline_autorefresh",
+        "offline_check_now",
+        "offline_checking",
+        "offline_stream_waiting",
+    ):
+        assert key in I18N_JS
+
+
+def test_offline_monitor_patches_fetch_and_auto_reloads_after_health_probe():
+    assert "const OFFLINE_RECHECK_MS=2500" in UI_JS
+    assert "window.fetch=async function(...args)" in UI_JS
+    assert "window.addEventListener('offline',()=>showOfflineBanner('browser'))" in UI_JS
+    assert "window.addEventListener('online',()=>{if(_offlineVisible)checkOfflineRecoveryNow();})" in UI_JS
+    assert "setInterval(()=>{checkOfflineRecoveryNow();},OFFLINE_RECHECK_MS)" in UI_JS
+    assert "new URL('health',document.baseURI||location.href)" in UI_JS
+    assert "window.location.reload()" in UI_JS
+
+
+def test_offline_recovery_probe_is_serialized_and_stops_timer_before_reload():
+    assert "let _offlineProbePromise=null" in UI_JS
+    assert "let _offlineHealthProbePromise=null" in UI_JS
+    assert "if(!_offlineVisible)return false;" in UI_JS
+    assert "if(!_offlineVisible&&!_offlineFetchPatched)return false;" not in UI_JS
+    assert "finally{_offlineProbePromise=null;}" in UI_JS
+    assert "finally{_offlineHealthProbePromise=null;}" in UI_JS
+    reload_idx = UI_JS.find("window.location.reload()")
+    assert reload_idx != -1
+    assert UI_JS.rfind("_stopOfflineProbeTimer();", 0, reload_idx) != -1
+
+
+def test_fetch_typeerror_is_gated_by_health_probe_not_blind_banner():
+    fetch_patch = UI_JS.split("window.fetch=async function(...args){", 1)[1].split("function initOfflineMonitor", 1)[0]
+    assert "function _isAbortError(e)" in UI_JS
+    assert "e instanceof TypeError&&!_isAbortError(e)" in fetch_patch
+    assert "void _probeOfflineRecovery().then(ok=>{if(!ok)showOfflineBanner('network');})" in fetch_patch
+    assert "if(!_browserReportsOnline())showOfflineBanner('browser');" in fetch_patch
+    assert "e instanceof TypeError||!_browserReportsOnline()" not in fetch_patch
+
+
+def test_sse_network_error_defers_to_offline_banner_instead_of_inline_error():
+    assert "function _deferStreamErrorIfOffline()" in MESSAGES_JS
+    assert "t('offline_stream_waiting')" in MESSAGES_JS
+    assert "if(_deferStreamErrorIfOffline()) return;" in MESSAGES_JS
+    error_handler = MESSAGES_JS.split("source.addEventListener('error',async e=>{", 1)[1].split("source.addEventListener('cancel'", 1)[0]
+    assert error_handler.find("_deferStreamErrorIfOffline()") < error_handler.rfind("_handleStreamError()")
@@ -427,10 +427,11 @@ class TestMessagePaginationFrontend:
        assert "async function _ensureAllMessagesLoaded" in SESSIONS_JS

    def test_scroll_to_top_triggers_loading(self):
-        """Scroll event handler must trigger _loadOlderMessages near top."""
+        """Scroll event handler must trigger _loadOlderMessages near top when opt-in is enabled."""
        UI_JS = (REPO / "static" / "ui.js").read_text(encoding="utf-8")

-        assert "el.scrollTop<80" in UI_JS
+        assert "const olderPrefetchPx=Math.max(600,el.clientHeight*1.5)" in UI_JS
+        assert "_isSessionEndlessScrollEnabled()&&el.scrollTop<olderPrefetchPx" in UI_JS
        assert "_loadOlderMessages" in UI_JS

    def test_load_older_indicator_in_render(self):
@@ -18,6 +18,7 @@ MANIFEST = ROOT / "static" / "manifest.json"
 SW = ROOT / "static" / "sw.js"
 INDEX = ROOT / "static" / "index.html"
 ROUTES = ROOT / "api" / "routes.py"
+AUTH = ROOT / "api" / "auth.py"


 class TestManifest:
@@ -107,6 +108,22 @@ class TestServiceWorker:
            "sw.js must await/then the caches.match() result before applying the fallback"
        )

+    def test_sw_shell_assets_are_network_first_with_cache_fallback(self):
+        """Local hotfixes can change JS/CSS while WEBUI_VERSION stays unchanged.
+
+        If shell assets are cache-first, the browser can keep executing stale
+        sessions.js even though the server/curl already returns patched source.
+        Network-first preserves offline fallback without hiding local fixes.
+        """
+        src = SW.read_text(encoding="utf-8")
+        assert "Shell assets: network-first with cache fallback" in src
+        assert "fetch(event.request).then((response)" in src
+        assert "caches.open(CACHE_NAME).then((cache) => cache.put(event.request, clone))" in src
+        assert ".catch(() => caches.match(event.request)" in src
+        assert "if (cached) return cached;" not in src, (
+            "shell assets must not be cache-first; stale JS can survive hard refresh"
+        )
+
    def test_sw_never_caches_api_responses(self):
        """Defensive: the SW must not cache responses from /api/* paths.
        Currently enforced by early-return before the shell-asset cache block."""
@@ -162,6 +179,15 @@ class TestPWARoutes:
            "the expected scope"
        )

+    def test_sw_is_public_auth_path(self):
+        src = AUTH.read_text(encoding="utf-8")
+        public_idx = src.find("PUBLIC_PATHS")
+        assert public_idx != -1, "auth.py must define PUBLIC_PATHS"
+        block = src[public_idx:public_idx + 400]
+        assert "'/sw.js'" in block, (
+            "/sw.js must be public so service-worker updates never return login HTML"
+        )
+

 class TestIndexHtmlIntegration:
    def test_index_links_manifest(self):
@@ -0,0 +1,32 @@
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+CONFIG_PY = (ROOT / "api" / "config.py").read_text(encoding="utf-8")
+BOOT_JS = (ROOT / "static" / "boot.js").read_text(encoding="utf-8")
+INDEX_HTML = (ROOT / "static" / "index.html").read_text(encoding="utf-8")
+PANELS_JS = (ROOT / "static" / "panels.js").read_text(encoding="utf-8")
+UI_JS = (ROOT / "static" / "ui.js").read_text(encoding="utf-8")
+I18N_JS = (ROOT / "static" / "i18n.js").read_text(encoding="utf-8")
+
+
+def test_endless_scroll_is_opt_in_setting():
+    assert '"session_endless_scroll": False' in CONFIG_PY
+    assert '"session_endless_scroll"' in CONFIG_PY
+    assert 'id="settingsSessionEndlessScroll"' in INDEX_HTML
+    assert 'data-i18n="settings_label_session_endless_scroll"' in INDEX_HTML
+    assert 'data-i18n="settings_desc_session_endless_scroll"' in INDEX_HTML
+    assert "session_endless_scroll: !!($('settingsSessionEndlessScroll')||{}).checked" in PANELS_JS
+    assert "window._sessionEndlessScrollEnabled=!!s.session_endless_scroll" in BOOT_JS
+    assert "window._sessionEndlessScrollEnabled=false" in BOOT_JS
+
+
+def test_scroll_listener_prefetches_older_messages_only_when_enabled():
+    assert "function _isSessionEndlessScrollEnabled" in UI_JS
+    assert "const olderPrefetchPx=Math.max(600,el.clientHeight*1.5)" in UI_JS
+    assert "_isSessionEndlessScrollEnabled()&&el.scrollTop<olderPrefetchPx" in UI_JS
+    assert "el.scrollTop<80 && typeof _messagesTruncated" not in UI_JS
+
+
+def test_endless_scroll_i18n_keys_exist_for_each_locale():
+    assert I18N_JS.count("settings_label_session_endless_scroll") == I18N_JS.count("settings_label_workspace_panel_open")
+    assert I18N_JS.count("settings_desc_session_endless_scroll") == I18N_JS.count("settings_desc_workspace_panel_open")
@@ -0,0 +1,77 @@
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+UI_JS = (REPO / "static" / "ui.js").read_text(encoding="utf-8")
+BOOT_JS = (REPO / "static" / "boot.js").read_text(encoding="utf-8")
+INDEX_HTML = (REPO / "static" / "index.html").read_text(encoding="utf-8")
+STYLE_CSS = (REPO / "static" / "style.css").read_text(encoding="utf-8")
+I18N_JS = (REPO / "static" / "i18n.js").read_text(encoding="utf-8")
+PANELS_JS = (REPO / "static" / "panels.js").read_text(encoding="utf-8")
+CONFIG_PY = (REPO / "api" / "config.py").read_text(encoding="utf-8")
+
+
+def _function_body(src: str, signature: str) -> str:
+    start = src.index(signature)
+    brace = src.index("{", start)
+    depth = 0
+    for i in range(brace, len(src)):
+        if src[i] == "{":
+            depth += 1
+        elif src[i] == "}":
+            depth -= 1
+            if depth == 0:
+                return src[start : i + 1]
+    raise AssertionError(f"function body not found: {signature}")
+
+
+def test_session_jump_buttons_are_opt_in_and_keep_existing_bottom_button():
+    assert '"session_jump_buttons": False' in CONFIG_PY
+    assert '"session_jump_buttons"' in CONFIG_PY
+    assert "window._sessionJumpButtonsEnabled=!!s.session_jump_buttons" in BOOT_JS
+    assert "window._sessionJumpButtonsEnabled=false" in BOOT_JS
+    assert "session_jump_buttons: !!($('settingsSessionJumpButtons')||{}).checked" in PANELS_JS
+
+    scroll_listener = UI_JS[UI_JS.index("el.addEventListener('scroll'") : UI_JS.index("})();", UI_JS.index("el.addEventListener('scroll'"))]
+    assert "if(btn) btn.style.display=_scrollPinned?'none':'flex'" in scroll_listener
+    assert "!_isSessionJumpButtonsEnabled()||_scrollPinned" not in UI_JS
+
+
+def test_jump_to_session_start_button_loads_full_history_and_scrolls_top():
+    jump = _function_body(UI_JS, "async function jumpToSessionStart")
+    update = _function_body(UI_JS, "function _updateSessionStartJumpButton")
+
+    assert 'id="jumpToSessionStartBtn"' in INDEX_HTML
+    assert 'class="session-jump-btn session-jump-btn--start"' in INDEX_HTML
+    assert "data-i18n=\"session_jump_start\"" in INDEX_HTML
+    assert "data-i18n=\"session_jump_end\"" in INDEX_HTML
+    assert "data-i18n-aria-label=\"session_jump_start_label\"" in INDEX_HTML
+    assert "data-i18n-aria-label=\"session_jump_end_label\"" in INDEX_HTML
+
+    assert "_ensureAllMessagesLoaded" in jump
+    assert "_messageRenderWindowSize=Math.max(_currentMessageRenderWindowSize(),_messageRenderableMessageCount())" in jump
+    assert "renderMessages({ preserveScroll:true })" in jump
+    assert "container.scrollTop=0" in jump
+    assert "btn.style.display=(hasSession&&canRevealStart&&awayFromStart)?'flex':'none'" in update
+
+
+def test_session_jump_buttons_match_pill_layout_without_regressing_default_arrow():
+    assert ".session-jump-btn" in STYLE_CSS
+    assert ".session-jump-btn--start{top:16px" in STYLE_CSS
+    assert ".session-jump-btn__text{display:none" in STYLE_CSS
+    assert ".messages.session-nav-enabled .scroll-to-bottom-btn" in STYLE_CSS
+    assert ".messages.session-nav-enabled .session-jump-btn__text{display:inline" in STYLE_CSS
+    assert "classList.toggle('session-nav-enabled',_isSessionJumpButtonsEnabled())" in UI_JS
+
+
+def test_session_jump_buttons_are_i18n_localized_in_text_tooltip_and_aria():
+    for key in [
+        "session_jump_start",
+        "session_jump_start_label",
+        "session_jump_end",
+        "session_jump_end_label",
+        "settings_label_session_jump_buttons",
+        "settings_desc_session_jump_buttons",
+    ]:
+        assert I18N_JS.count(f"{key}:") >= 8, f"missing locale entries for {key}"
+    assert "document.querySelectorAll('[data-i18n-aria-label]')" in I18N_JS
+    assert "el.setAttribute('aria-label', val)" in I18N_JS