feat: LUKS2 encryption, boot sequence fixes, onboarding auth, CI/CD

- LUKS2 full-partition encryption for /var/lib/archipelago/ (TASK-42)
  4-partition layout: BIOS + EFI + root (30GB) + encrypted data
  AES-256-XTS with AES-NI detection, ChaCha20 fallback for ARM
  Auto-unlock via crypttab + random key file

- Fix EFI boot errors: remove shim-signed, clean shim artifacts
- Fix first-boot sequence: always show boot animation before onboarding
- Fix stale localStorage causing login instead of onboarding (BUG-47)

- Add auth.setup + auth.isSetup RPC handlers for password on clean install
- Add onboarding methods to UNAUTHENTICATED_METHODS (DID sign 403 fix)

- FileBrowser bundled in unbundled ISO, fix auto-login Secure cookie (BUG-46)
- Kiosk mode: xorg/chromium in rootfs, toggle script, MOTD instructions

- Add Gitea Actions CI/CD workflow for automatic ISO builds

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

neode-ui/src/api/filebrowser-client.ts

@@ -65,7 +65,9 @@ class FileBrowserClient {
       const token = text.replace(/^"|"$/g, '')
       // Store token as cookie — the only auth mechanism we use
       const expires = new Date(Date.now() + 24 * 60 * 60 * 1000).toUTCString()
-      document.cookie = `auth=${token}; path=/app/filebrowser; SameSite=Strict; Secure; expires=${expires}`
+      // Only set Secure flag on HTTPS — on HTTP it silently prevents the cookie from being stored
+      const secure = window.location.protocol === 'https:' ? '; Secure' : ''
+      document.cookie = `auth=${token}; path=/app/filebrowser; SameSite=Lax${secure}; expires=${expires}`
       this._authenticated = true
       return true
     } catch {