feat(ui): add custom branding and Chinese localization

CLAUDE.md

@@ -140,7 +140,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 | **Attachments**  | `src/attachment-registry.ts`, `src/attachment-magic.ts`, `src/generated-artifact-attachments.ts` (Codex `Saved to:` artifacts), `src/session-attachment-history.ts`, `src/document-preview-cache.ts`, `src/document-thumbnailer.ts`, `src/document-conversion-limiter.ts`, `src/config/attachment-guard.ts`                                                                                                                                                                                                                                                                  | See Key Patterns                                                                                                                      |
 | **Plan**         | `src/plan-orchestrator.ts`, `src/prompts/*.ts`, `src/templates/` (`claude-md.ts` + `case-template.md`, the CLAUDE.md scaffold generated into new cases)                                                                                                                                                                                                                                                                                                                                                                                                                      |                                                                                                                                       |
 | **Web**          | `src/web/server.ts` ★, `src/web/sse-events.ts`, `src/web/routes/*.ts` (20 route modules + barrel; `session-routes.ts` ★), `src/web/route-helpers.ts`, `src/web/ports/*.ts`, `src/web/middleware/auth.ts`, `src/web/schemas.ts`, `src/web/self-update.ts`, `src/web/plan-usage-latest.ts`, `src/web/ws-connection-registry.ts` (per-tab WS supersede), `src/web/heic-jpeg-converter.ts` + `heic-jpeg-worker.ts` (HEIC→JPEG off-thread)                                                                                                                                        |                                                                                                                                       |
-| **Frontend**     | `src/web/public/app.js` (~4K lines, core) + 6 infra modules (`constants.js`, `mobile-handlers.js`, `voice-input.js`, `notification-manager.js`, `keyboard-accessory.js`, `sanitize-html.js` — DOMPurify mXSS allowlist, COD-56) + 10 domain modules (`terminal-ui.js`, `respawn-ui.js`, `ralph-panel.js`, `orchestrator-panel.js`, `ultracode-panel.js`, `cron-ui.js`, `settings-ui.js`, `panels-ui.js`, `admin-ui.js`, `session-ui.js`) + 6 feature modules (`ralph-wizard.js`, `api-client.js`, `subagent-windows.js`, `ultracode-windows.js`, `input-cjk.js`, `image-input.js`) + `sw.js` | `ultracode-windows.js` = floating run windows w/ tab connector lines (additional to the dock panel)                                   |
+| **Frontend**     | `src/web/public/app.js` (~4K lines, core) + 7 infra modules (`constants.js`, `i18n.js`, `mobile-handlers.js`, `voice-input.js`, `notification-manager.js`, `keyboard-accessory.js`, `sanitize-html.js` — DOMPurify mXSS allowlist, COD-56) + 10 domain modules (`terminal-ui.js`, `respawn-ui.js`, `ralph-panel.js`, `orchestrator-panel.js`, `ultracode-panel.js`, `cron-ui.js`, `settings-ui.js`, `panels-ui.js`, `admin-ui.js`, `session-ui.js`) + 6 feature modules (`ralph-wizard.js`, `api-client.js`, `subagent-windows.js`, `ultracode-windows.js`, `input-cjk.js`, `image-input.js`) + `sw.js` | `i18n.js` owns English/Simplified Chinese UI localization + user-facing branding; `ultracode-windows.js` = floating run windows w/ tab connector lines                                   |
 | **Types**        | `src/types/index.ts` (barrel) → 19 domain files (incl. `workflow-run.ts`, `search.ts`, `cron.ts`, `user.ts`); also `src/types.ts` root re-export                                                                                                                                                                                                                                                                                                                                                                                                                                        | See `@fileoverview` in index.ts                                                                                                       |
 
 ★ = Large, central file (>50KB) — read its `@fileoverview` first. All files have `@fileoverview` JSDoc — read that before diving in. Discovery aid: `grep -l '@fileoverview' src/web/routes/*.ts` lists all route modules; same grep works for `src/types/`, `src/web/public/*.js`.
@@ -208,7 +208,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 ### Frontend
 
-Frontend JS modules have `@fileoverview` with `@dependency`/`@loadorder` tags. Load order: `constants.js`(1) → `mobile-handlers.js`(2) → `voice-input.js`(3) → `notification-manager.js`(4) → `keyboard-accessory.js`(5) → `input-cjk.js`(5.5) → `sanitize-html.js`(5.6) → `app.js`(6) → `terminal-ui.js`(7) → `respawn-ui.js`(8) → `ralph-panel.js`(9) → `orchestrator-panel.js`(9.5) → `cron-ui.js`(9.7) → `settings-ui.js`(10) → `panels-ui.js`(11) → `ultracode-panel.js`(11.5) → `admin-ui.js`(11.7) → `session-ui.js`(12) → `ralph-wizard.js`(13) → `api-client.js`(14) → `subagent-windows.js`(15) → `ultracode-windows.js`(15.5) → `image-input.js`(16). `input-cjk.js` handles CJK IME composition via an always-visible textarea below the terminal (`window.cjkActive` blocks xterm's onData).
+Frontend JS modules have `@fileoverview` with `@dependency`/`@loadorder` tags. Load order: `constants.js`(1) → `i18n.js`(1.5) → `mobile-handlers.js`(2) → `voice-input.js`(3) → `notification-manager.js`(4) → `keyboard-accessory.js`(5) → `input-cjk.js`(5.5) → `sanitize-html.js`(5.6) → `app.js`(6) → `terminal-ui.js`(7) → `respawn-ui.js`(8) → `ralph-panel.js`(9) → `orchestrator-panel.js`(9.5) → `cron-ui.js`(9.7) → `settings-ui.js`(10) → `panels-ui.js`(11) → `ultracode-panel.js`(11.5) → `admin-ui.js`(11.7) → `session-ui.js`(12) → `ralph-wizard.js`(13) → `api-client.js`(14) → `subagent-windows.js`(15) → `ultracode-windows.js`(15.5) → `image-input.js`(16). `i18n.js` translates static + newly inserted application DOM while skipping terminal/response/file/user-name surfaces; `input-cjk.js` handles CJK IME composition via an always-visible textarea below the terminal (`window.cjkActive` blocks xterm's onData).
 
 **Command palette + shortcut registry** (COD-151/153/157/192, #146): `Ctrl/Cmd/Alt+K` opens the session palette (fuzzy search over live sessions; "Browse all sessions" → the Session Manager modal backed by `GET /api/sessions/unified`); the quick-start case `<select>` is fronted by a searchable picker (`buildCasePickerOptions`/`formatCasePickerLabel` — remote cases render `name @ hostId`). Shortcuts live in a rebindable registry (`DEFAULT_SHORTCUTS`/`getShortcutRegistry()`/`matchesShortcutEvent()` in app.js; overrides persist under `settings.shortcutOverrides` via `saveAppSettingsToStorage`); App Settings → Shortcuts renders capture/disable rows; `Ctrl+?` opens the registry-driven overlay (footer links to the full `#helpModal` reference). ⚠️ Palette-chord keys must ALSO be swallowed in `attachCustomKeyEventHandler` (terminal-ui.js) or xterm writes the control byte (0x0B) into the PTY. ⚠️ `saveAppSettings()` rebuilds settings from the DOM — keys edited elsewhere (`shortcutOverrides`, `showTokenCount`, `showCost`) need explicit `_prev` carry-over.
 
@@ -228,6 +228,8 @@ Frontend JS modules have `@fileoverview` with `@dependency`/`@loadorder` tags. L
 
 **Theme skins** (App Settings → Display): the `skin` setting selects a palette via a `data-skin` attribute on `<html>`. Values: `daylight-blue` (default), `daylight-green`, `og` (OG Codeman). CSS lives under `[data-skin="…"]` blocks in `styles.css`. To avoid a flash-of-wrong-theme, an **inline pre-paint script** in `index.html` (`<head>`) reads `localStorage['codeman:skin']` and sets `data-skin` before first paint; `settings-ui.js` `applySkin()` applies it live on save (sets `html[data-skin]` + `window.__codemanSkin`, syncs the standalone `codeman:skin` key with the settings blob, and calls terminal-ui.js `applyTerminalSkin()` to re-theme live terminals). `skin` is a **per-device/client-only** setting — it's destructured OUT of the server payload (settings-ui.js, alongside `localEchoEnabled`/`cjkInputEnabled`/`extendedKeyboardBar`), so it does NOT sync across devices.
 
+**Custom branding + UI language** (App Settings → Display → Branding & Language): `displayName` is schema-validated (trimmed, 1–40 chars), server-synced, and changes user-facing browser branding/window titles only — NEVER rename npm package/CLI/API/storage/CSS/protocol identifiers. `language` is a per-device `en`/`zh-CN` display key, stripped from the server payload. `i18n.js` keeps English as the canonical source/fallback, observes newly inserted application DOM for dynamic copy, preserves source strings so live EN↔ZH switching is reversible, and skips terminal/response/file/session-name/user-content surfaces. User display names flow through `textContent`/attribute APIs and the server title's HTML escaper, never `innerHTML`.
+
 **Respawn presets**: `solo-work` (3s/60min), `subagent-workflow` (45s/240min), `team-lead` (90s/480min), `ralph-todo` (8s/480min), `overnight-autonomous` (10s/480min).
 
 **Keyboard shortcuts**: Escape (close), Ctrl+? (shortcut overlay), Ctrl/Cmd/Alt+K (session palette), Ctrl+W (kill), Ctrl+Tab (next), Alt+[/] (prev/next tab), Alt+1-9 (switch tab), Ctrl+Shift+{/} (move tab left/right), Shift+Enter or Ctrl+Enter (newline), Ctrl+L (clear), Ctrl+Shift+R (restore size), Ctrl+Shift+V (voice input), Ctrl/Cmd +/- (font), Shift+Wheel (local scrollback when mouse passthrough is active). Rebindable via the registry (see Command palette above).