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/desktop/src-tauri/src/lib.rs

@@ -0,0 +1,21 @@
+// Parking System desktop shell — entry point.
+//
+// Intentionally minimal: build the default Tauri app and run it. The window
+// config (kiosk, fullscreen, which URL/assets to load) lives in tauri.conf.json.
+// No custom commands are registered — the renderer (the @parking/web SPA) reaches
+// the backend over HTTP to the local Fastify server, NOT through Tauri IPC. This
+// keeps the shell a thin presentation wrapper with a deny-by-default native
+// surface (see wiki/decisions/desktop-shell-tauri.md).
+
+#[cfg_attr(mobile, tauri::mobile_entry_point)]
+pub fn run() {
+    tauri::Builder::default()
+        // Auto-update: the JS side (apps/web) checks on launch, prompts the
+        // operator, and installs + relaunches on confirm. These plugins expose
+        // the update check/install and the relaunch to that flow. The updater
+        // endpoint + signing pubkey live in tauri.conf.json.
+        .plugin(tauri_plugin_updater::Builder::new().build())
+        .plugin(tauri_plugin_process::init())
+        .run(tauri::generate_context!())
+        .expect("error while running the Parking System desktop shell");
+}