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

wiki/concepts/append-only-event-chain.md

@@ -69,10 +69,21 @@ secure element is a new `Signer` impl with no `EventLog` change; each event stor
 so old events stay verifiable.
 
 > ⚠️ The software signer makes the chain **self-consistent + tamper-evident**, but **not
-> unforgeable by someone who owns the host** — only the ATECC608's non-extractable key gives
-> property (3) above. Until the chip is wired, the chain detects tampering by *outsiders* and
-> *accidental* corruption, but an operator with the signing key + DB access could re-sign a
-> forged chain. This is the central reason #6 matters.
+> unforgeable by someone who owns the host** — only a non-extractable key in a secure element
+> ([[atecc608]] on embedded, or the host **[[tpm|TPM]]** on a PC appliance) gives property (3) above.
+> Until that is wired, the chain detects tampering by *outsiders* and *accidental* corruption, but an
+> operator (or anyone who pulls the SSD and reads the `.env`) has the HMAC key and could **edit a row
+> and re-sign the whole chain undetectably**. This is the central reason #6 matters.
+
+> **Pull-the-disk attack (traced 2026-06-21).** Removing the SSD, editing `parking.sqlite` on
+> another machine, and rebooting: any blind edit/delete/reorder **breaks the chain** and
+> `verifyChain()` pinpoints it (bad signature / index gap / prevHash mismatch / unknown keyId). **But
+> two gaps:** (a) **nothing runs `verifyChain()` at startup today** — the tamper is *detectable but
+> undetected* until something invokes verification (wire a boot-time self-check that at least logs/flags
+> a signed alarm — fail-open on exit still governs; this is [[open-questions]] #13); and (b) with the
+> *software* signer the key is on the same disk, so the attacker can re-sign and pass verification —
+> only a secure-element key ([[tpm]]/[[atecc608]]) closes that. [[tpm|TPM-sealed]] LUKS additionally
+> stops the disk **mounting** off-host at all.
 
 ### Business-layer event types (the ledger)