feat(desktop): Tauri v2 kiosk shell — maximized window, prod right-click block, auto-update + code-signing

Add apps/desktop, a thin Tauri v2 shell wrapping the SAME @parking/web SPA so
the desktop and browser UIs never drift: dev loads the Vite dev server (HMR),
prod bundles the web app's dist/. No business logic in the shell (device/auth/
ledger stay in @parking/server); deny-by-default capabilities.

apps/web (single UI source of truth):
- lib/origin.ts: centralize the backend origin (API_BASE/apiUrl/wsUrl from
  VITE_API_BASE); no-op in the browser, lets the desktop build target Fastify.
- lib/kiosk.ts: block the right-click context menu in PROD only (dev keeps it +
  devtools).
- lib/desktop-updater.ts: prompt-on-update auto-update (no-op in browser/offline)
  → downloadAndInstall + relaunch; i18n update.* keys (sq+en).
- .env.production: VITE_API_BASE wired to the Fastify origin for the bundle.

Desktop:
- window starts maximized (not fullscreen — operator keeps OS access).
- auto-update via tauri-plugin-updater + -process; self-hosted endpoint is a
  PLACEHOLDER to fill in. Updater keypair: pubkey embedded in tauri.conf.json;
  private key + password kept OUTSIDE the repo (~/.parking-updater-keys) and as
  TAURI_SIGNING_* build secrets.
- Turbo build is a no-op; the real signed bundle is `pnpm --filter
  @parking/desktop bundle` (verified → .deb/.rpm/.AppImage + .sig signatures).

Verified: cargo check clean; turbo run build lint 14/14 green; i18n parity holds;
no key/sig/bundle artifacts in the repo.

Wiki (security + desktop analysis recorded alongside):
- new concepts/tpm.md (TPM 2.0: how it works, sealed-LUKS auto-unlock + non-
  extractable signing key, limits — live-root, bus-sniff — TPM-vs-ATECC608 by
  platform).
- new decisions/desktop-shell-tauri.md (Tauri v2 over Electron; best-case Ubuntu
  26.04 LTS, worst-case Windows+WSL → kiosk browser; full as-built).
- pull-the-disk attack trace on append-only-event-chain; ATECC608 not-in-a-PC
  caveat; cross-links from disk-os-hardening / threat-model.
- open-questions #11 (appliance WebKitGTK), #12 (TPM hardening impl), #13
  (startup verifyChain self-check); index/overview/log/standing-decisions.

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V

apps/web/src/lib/desktop-updater.ts

@@ -0,0 +1,51 @@
+// Desktop auto-update — prompt-on-update flow.
+//
+// Runs ONLY inside the Tauri desktop shell; a plain browser has no updater, so
+// this is a guarded no-op there. On launch it checks the configured update
+// endpoint (tauri.conf.json → plugins.updater); if a signed newer version is
+// available it asks the operator, then downloads + installs and relaunches.
+//
+// The plugins are imported dynamically so the browser build never bundles them
+// and never tries to resolve the Tauri APIs. Offline-first: a failed check (no
+// network — the appliance is usually offline) is swallowed; updates only happen
+// when someone has brought the box online (e.g. a phone hotspot) on purpose.
+
+/** True when running inside the Tauri webview (not a normal browser). */
+function inTauri(): boolean {
+  return typeof window !== "undefined" && "__TAURI_INTERNALS__" in window;
+}
+
+export interface UpdatePrompt {
+  /** Newer version string offered by the server. */
+  version: string;
+  /** Release notes, if the server provided them. */
+  notes?: string;
+}
+
+/**
+ * Check for an update. If one is available, calls `confirm` (your UI) with the
+ * version/notes; when it resolves true, downloads + installs and relaunches.
+ * No-op (resolves silently) in the browser or when no update / offline.
+ */
+export async function checkForDesktopUpdate(
+  confirm: (info: UpdatePrompt) => Promise<boolean>,
+): Promise<void> {
+  if (!inTauri()) return;
+  try {
+    const { check } = await import("@tauri-apps/plugin-updater");
+    const update = await check();
+    if (!update) return; // up to date
+
+    const accepted = await confirm({ version: update.version, notes: update.body });
+    if (!accepted) return;
+
+    // Download + install the signed update (signature verified against the
+    // pubkey in tauri.conf.json), then relaunch into the new version.
+    await update.downloadAndInstall();
+    const { relaunch } = await import("@tauri-apps/plugin-process");
+    await relaunch();
+  } catch {
+    // Offline / endpoint unreachable / no update server yet → ignore. The app
+    // keeps running on the current version; checking again next launch.
+  }
+}