fix(custom-model): act on the draft review — unparseable onclick, unwrapped envelope, wrong-session apply, missing lock, no tests

Addresses every blocker, both majors, and all but one minor from the
maintainer's review of the draft PR.

Blockers:

1. Every generated inline onclick was unparseable. JSON.stringify's own
   double quotes terminated the double-quoted HTML attribute at the first
   one, leaving btn.onclick null on every picker entry and every Discover/
   Edit/Delete button. Fixed with escapeHtml(JSON.stringify(...)) per
   argument, the same idiom deleteCase's onclick already uses four lines
   away in session-ui.js. This also closes the live-HTML-injection route
   through modelId (server-controlled, from the endpoint's own /v1/models
   reply): with quoting intact, a `>` inside it can no longer terminate the
   <button> tag early.
2. GET /api/model-endpoints wraps its body in the {success,data} envelope
   like every other /api route (server.ts's preSerialization hook applies
   to arrays too), so Array.isArray(hosts) was always false in production
   and the picker/settings panel silently saw nothing. Both call sites now
   go through _apiJson(), which already exists for exactly this.
3. A failed or declined run*() (missing CLI, isBusy, a caught exception)
   returns normally without ever changing activeSessionId, so the apply
   step used to silently re-point and restart whatever session the user was
   already looking at. runCustomModelEntry() now snapshots activeSessionId
   before the launch and requires it to have actually changed.

Majors:

4. Routes the launch through run() itself via a temporary _runMode swap
   (never persisted — setRunMode() would sync it to the server) instead of
   a parallel hardcoded dispatch table, so a custom-model launch now holds
   the same _runInFlight lock every other Run click gets. This also
   resolves the "hardcoded runners map contradicts the PR's own design"
   minor: dispatch is run()'s own, so a CLI whose customModelInjection
   recipe lands later needs no update here.
5. New test/custom-model-run-menu-ui.test.ts drives the real session-ui.js
   against a JSDOM window (runScripts:"dangerously" — this JSDOM only ever
   parses markup this module generated itself) for exactly the DOM-level
   facts the review said needed no Playwright and no tmux: a generated
   button's onclick genuinely compiles and fires, a dangerous modelId never
   produces a live element, the envelope unwrap works, the session-changed
   guard holds, run() actually gets called (proving the in-flight lock
   engages), and _runMode is restored afterward. Confirmed against the
   pre-fix code first (reproduces btn.onclick === null exactly) so this
   isn't a vacuous pass. Plus new tests in custom-model-routes.test.ts and
   render-index-html.test.ts for the other fixes below.

Minors:

- Generated entries now filter through isCliAvailable(), matching
  _refreshRunModeAvailability's own gating of the stock entries.
- The CRUD panel is now gated on customModelEndpointsEnabled
  (applyCustomModelEndpointsVisibility(), wired to the toggle's onchange
  and to settings-modal open) instead of always rendering; the endpoint GET
  no longer fires unconditionally either.
- API keys are never handed back to the browser on GET, POST or PUT —
  redactApiKey() replaces the field with a computed apiKeySet: boolean, and
  a PUT with no apiKey now keeps the stored one server-side
  (applyStoredApiKey()) instead of the client resending a value it was
  never given. New tests cover both directions (kept vs. replaced) by
  observing the actual auth header a subsequent discovery request sends.
- "+ Add endpoint" hides for a non-admin in multi-user mode
  (_applyCustomModelAdminGate(), also wired to admin-ui.js's codeman:me
  event, since the real role can resolve after settings were first opened)
  — endpoint writes were already admin-only server-side, but the button
  used to render for everyone and eat a 403.
- design doc (custom-model-endpoints-plan.md §4) now says up front that its
  toolbar-button design was superseded by the Run-menu picker.
- docs/api-reference.md gained a Custom Model Endpoints section (every
  route, the apiKeySet/defaultModelId contract, the restart mechanics).
- Wiki page now covers un-pointing a session (curl/delete, no UI yet) and
  that the picker is desktop-only for now.
- .set-inline-form uses --control-bg instead of a hardcoded black alpha
  (CLAUDE.md already records that exact literal turning the settings
  preview into a grey slab on light skins), .run-mode-custom-models gets
  the same gap: 2px .run-mode-menu's own flex gap only applies one level
  up, and the index.html comment naming the wrong function is fixed.
- __codemanCustomModelClis's JSON is now escaped against a literal
  </script> (CliEntry.label is user-clis.json-settable, unlike
  __codemanCliAvailable's booleans-only payload) via a new exported
  escapeScriptJson(), pure and unit-tested without needing a WebServer.
- Added defaultModelId + the new /v1/model-endpoints routes to
  docs/api-reference.md; left the "no zh-CN for the new Models-section
  group" minor unaddressed only insofar as the wider Models section (task
  routing, thinking effort, etc.) has never had zh-CN coverage either —
  everything this PR itself introduces (labels, hints, button text, the
  Run-menu's "Custom Endpoints" header) IS translated in i18n.js.

Regression caught while fixing #4: the admin-gate's codeman:me listener is
a module-level document.addEventListener() call, which threw in
run-mode-ui.test.ts's minimal vm-context fake document and failed all 10
of that file's tests. Fixed with optional chaining before it ever reached
the branch this commit lands on; full targeted suite (route tests,
structural guards, every settings-ui.js-loading frontend test) reverified
green afterward.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RqZeHrRS6DYcGcGX2p9EwG

src/web/public/i18n.js

@@ -286,6 +286,31 @@
     'Prompt sent': '提示已发送',
     'Inserted, press Enter in the terminal to send': '已插入，在终端中按 Enter 发送',
     'Could not reach the session': '无法连接到会话',
+    'Custom model endpoints': '自定义模型端点',
+    'Point a harness at your own OpenAI-compatible server (llama.cpp, vLLM, DGX Spark, Azure AI Foundry, OpenRouter) instead of its native cloud backend. When on, the Run menu offers an extra entry per harness that supports it, per saved endpoint.':
+      '让工具指向您自己的兼容 OpenAI 服务器（llama.cpp、vLLM、DGX Spark、Azure AI Foundry、OpenRouter），而非其原生云端后端。开启后，"运行"菜单会为每个支持此功能的工具、每个已保存的端点新增一个条目。',
+    'Enable custom model endpoints': '启用自定义模型端点',
+    'Adds a per-endpoint entry to the Run menu for every harness that can redirect to one.':
+      '为每个可重定向到端点的工具，在"运行"菜单中添加对应条目。',
+    'No endpoints yet. Add one below to point a harness at a local or cloud OpenAI-compatible server.':
+      '暂无端点。请在下方添加一个，以便将工具指向本地或云端的兼容 OpenAI 服务器。',
+    Discover: '发现模型',
+    '+ Add endpoint': '+ 添加端点',
+    'Add endpoint': '添加端点',
+    Id: 'ID',
+    'Short, stable — used in URLs, never shown to the CLI.': '简短且固定 — 用于 URL，不会展示给 CLI。',
+    Label: '标签',
+    'Base URL': '基础 URL',
+    'API key': 'API 密钥',
+    'Optional. Left blank on edit keeps the existing key.': '可选。编辑时留空将保留现有密钥。',
+    'Auth header': '认证请求头',
+    'Never send both — some servers hang indefinitely.': '切勿同时发送两者 — 部分服务器会因此无限期挂起。',
+    'Authorization: Bearer (default)': 'Authorization: Bearer（默认）',
+    'api-key header (Azure)': 'api-key 请求头（Azure）',
+    'Default model': '默认模型',
+    'What the Run-menu picker applies for this endpoint. Discover models first.':
+      '运行菜单选择器会为此端点应用该模型。请先发现可用模型。',
+    'Custom Endpoints': '自定义端点',
     'Subagent Options': '子智能体选项',
     'Enable Tracking': '启用跟踪',
     'Active Tab Only': '仅活动标签页',