feat(ui): add browser console served by the daemon

Introduce a minimal operations console reachable on a dedicated UI port
(default 8081), kept separate from the OpenAI-compatible API port.

- ts_web/ holds the SPA shell (index.html, app.css, vanilla app.js) with
  sidebar navigation for all views from readme.ui.md and a working
  Overview page backed by a new /_ui/overview JSON endpoint.
- scripts/bundle-ui.ts walks ts_web/ and emits ts_bundled/bundle.ts, a
  single generated module exporting every asset as base64. Mirrors the
  @stack.gallery/registry pattern so deno compile binaries embed the
  entire UI with no external filesystem dependency at runtime.
- ts/ui/server.ts (UiServer) serves assets from either the bundled map
  (default, prod) or directly from ts_web/ on disk (dev). The source is
  chosen per-config and can be overridden by UI_ASSET_SOURCE=disk|bundle.
  SPA fallback routes unknown extensionless paths to index.html.
- IModelGridConfig.ui block with enabled/port/host/assetSource defaults;
  config init writes the block, the normalizer fills in defaults on
  load, and the daemon starts/stops the UI server alongside the API.
- deno.json gains a bundle:ui task; compile:all now depends on it so
  released binaries always contain an up-to-date bundle. dev task sets
  UI_ASSET_SOURCE=disk for hot edits.
- ts_bundled/ is gitignored (generated on build).
- test/ui-server.smoke.ts exercises bundle and disk modes end to end
  (index, app.js, SPA fallback, /_ui/overview, 404).

ts/interfaces/config.ts

@@ -60,6 +60,28 @@ export interface IModelConfig {
   autoLoad: string[];
 }
 
+/**
+ * Browser-based operations console (UI) configuration.
+ * The UI is served on its own port, distinct from the OpenAI API port,
+ * so that the data plane stays clean.
+ */
+export interface IUiConfig {
+  /** Whether to start the UI server alongside the API */
+  enabled: boolean;
+  /** Port to bind the UI server to (default: 8081) */
+  port: number;
+  /** Host to bind the UI server to (default: '0.0.0.0') */
+  host: string;
+  /**
+   * Where UI assets come from.
+   *  - 'bundle': from the compiled-in `ts_bundled/bundle.ts` (default, required
+   *    for `deno compile` single-binary builds)
+   *  - 'disk':   read on demand from `ts_web/` for the dev loop
+   * Overridden at runtime by the `UI_ASSET_SOURCE` env var.
+   */
+  assetSource: 'bundle' | 'disk';
+}
+
 /**
  * Main ModelGrid configuration interface
  */
@@ -68,6 +90,8 @@ export interface IModelGridConfig {
   version: string;
   /** API server configuration */
   api: IApiConfig;
+  /** UI server configuration */
+  ui: IUiConfig;
   /** Docker configuration */
   docker: IDockerConfig;
   /** GPU configuration */