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_web/app.css

@@ -0,0 +1,187 @@
+:root {
+  color-scheme: dark;
+  --bg: #000;
+  --bg-1: #0b0b0d;
+  --bg-2: #14141a;
+  --fg: #e6e6ea;
+  --fg-dim: #8a8a92;
+  --border: #23232b;
+  --accent: #4357d9;
+  --ok: #2ecc71;
+  --warn: #f1c40f;
+  --err: #e74c3c;
+}
+
+* { box-sizing: border-box; }
+
+html, body {
+  margin: 0;
+  padding: 0;
+  height: 100%;
+  background: var(--bg);
+  color: var(--fg);
+  font-family: Inter, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+  font-size: 14px;
+}
+
+body {
+  display: grid;
+  grid-template-columns: 220px 1fr;
+}
+
+a { color: inherit; text-decoration: none; }
+
+.dim { color: var(--fg-dim); }
+
+.nav {
+  background: var(--bg-1);
+  border-right: 1px solid var(--border);
+  display: flex;
+  flex-direction: column;
+  height: 100vh;
+  position: sticky;
+  top: 0;
+}
+
+.nav-brand {
+  padding: 20px 16px 12px;
+  font-size: 15px;
+  font-weight: 600;
+  letter-spacing: 0.02em;
+  border-bottom: 1px solid var(--border);
+}
+
+.nav-items {
+  display: flex;
+  flex-direction: column;
+  padding: 8px 0;
+  flex: 1;
+  overflow-y: auto;
+}
+
+.nav-items a {
+  padding: 8px 16px;
+  color: var(--fg-dim);
+  border-left: 2px solid transparent;
+  transition: color 0.1s, background 0.1s, border-color 0.1s;
+}
+
+.nav-items a:hover {
+  color: var(--fg);
+  background: var(--bg-2);
+}
+
+.nav-items a.active {
+  color: var(--fg);
+  background: var(--bg-2);
+  border-left-color: var(--accent);
+}
+
+.nav-footer {
+  padding: 12px 16px;
+  border-top: 1px solid var(--border);
+  font-size: 12px;
+}
+
+main {
+  padding: 24px 32px;
+  overflow-y: auto;
+  height: 100vh;
+}
+
+h1 {
+  font-size: 18px;
+  font-weight: 600;
+  margin: 0 0 20px;
+  letter-spacing: 0.01em;
+}
+
+.cards {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
+  gap: 12px;
+  margin-bottom: 24px;
+}
+
+.card {
+  background: var(--bg-1);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  padding: 16px;
+}
+
+.card-label {
+  font-size: 11px;
+  text-transform: uppercase;
+  letter-spacing: 0.08em;
+  color: var(--fg-dim);
+  margin-bottom: 8px;
+}
+
+.card-value {
+  font-size: 22px;
+  font-weight: 600;
+}
+
+.card-sub {
+  font-size: 12px;
+  color: var(--fg-dim);
+  margin-top: 4px;
+}
+
+.status-dot {
+  display: inline-block;
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+  margin-right: 6px;
+  vertical-align: middle;
+}
+.status-dot.ok  { background: var(--ok); }
+.status-dot.warn{ background: var(--warn); }
+.status-dot.err { background: var(--err); }
+
+table {
+  width: 100%;
+  border-collapse: collapse;
+  background: var(--bg-1);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  overflow: hidden;
+}
+
+th, td {
+  text-align: left;
+  padding: 10px 14px;
+  border-bottom: 1px solid var(--border);
+  font-weight: normal;
+}
+
+th {
+  color: var(--fg-dim);
+  font-size: 11px;
+  text-transform: uppercase;
+  letter-spacing: 0.08em;
+  background: var(--bg-2);
+}
+
+tr:last-child td { border-bottom: none; }
+
+.placeholder {
+  padding: 40px;
+  text-align: center;
+  color: var(--fg-dim);
+  background: var(--bg-1);
+  border: 1px dashed var(--border);
+  border-radius: 6px;
+}
+
+.error {
+  background: var(--bg-1);
+  border: 1px solid var(--err);
+  color: var(--err);
+  padding: 12px 16px;
+  border-radius: 6px;
+  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
+  font-size: 12px;
+}