Implements ADR-0002. MediaRepository is an abstract-class DI token (matching
the Ed25519VerificationService pattern in app.config.ts) bound to
MockMediaRepository, an IndexedDB-backed implementation storing blobs
directly with lazily-created/revoked object URLs. Swapping to a real
HttpMediaRepository later is a one-line provider change.
No UI yet (Sprint 4 Task 3).
- Project editor: persist draft to localStorage, restore on reload,
last-saved/draft-restored status indicators, section/whole-draft reset
with confirmation.
- Extract shared QR/polling/expiry engine from TelegramLoginComponent
(shared/qr-login) and reuse it for a new admin login flow.
- Admin authentication kept fully separate from customer session:
own cookie/localStorage keys, signals, guard, and header interceptor
(core/admin-auth).
- ?login=true / ?adminLogin=true open the respective login dialog for
manual testing.
- Ed25519 challenge/verify interfaces (fail-closed no-op binding) ready
for backend delivery.
- Document autosave/reset/admin-auth/QR-reuse/Ed25519 model and the
remaining full-field-coverage gap in docs/Project-Editor.md.
