Lower the username floor to 3 characters on the admin-only write path
(account/channel set-username), separate from the 5-character self-service
minimum, since a deliberately short operator handle isn't the squatting the
higher floor guards against. Channel admin username assignment previously
had no length/format validation at all; this adds it.
Also adds three reference docs: the client's deep-link (tg://, owpg://)
surface, an OpenAPI 3.1 spec for both admin HTTP APIs (built from source,
not the stale docs/admin-panel-api.en.md), and a starter reserved-username
blocklist.
Keep bot credentials out of durable command results, fail bot deletion closed when session revocation fails, reject invalid scam/fake states at every write boundary, and make direct collectible grants a single replayable PostgreSQL aggregate.
Also lock admin gift sender/message limits and add regression coverage for rollback, replay, moderation constraints, and credential redaction.
Admin console additions (Layer 228):
- Give Gifts: dedicated tab with sorted Lottie/TGS gift picker + inline form; grant any catalog gift to a user/channel from 777000 (no charge)
- Upgraded/collectible delivery: mint a unique gift with admin-selected model/pattern/backdrop and custom number, or random/auto (DB FK + UNIQUE(gift_id,num) enforce invariants)
- SCAM/FAKE flags for users/channels (migration 0136) with configurable profile warning (TELESRV_SCAM_WARNING/TELESRV_FAKE_WARNING)
- Support toggle, force channel settings incl. gigagroup (migration 0137), username management, cosmetic color/emoji-status
- Emoji admin tab (custom emoji list + document IDs + Lottie/TGS preview)
- Bot management; soft UI / dark theme
Wired through Router -> admin.Service -> adminapi -> BFF -> React panel (en/zh/ru).
Sync telesrv 36eda30 (feat(communities): implement Layer 228 community aggregates).
Skipped telesrv docs changes per public sync rules; normalized the public appearance seed label.
Sync telesrv b96f2dd (feat(bot): complete keyboards callbacks and durable delivery).
Skipped private docs and preserved public README files per sync rules; normalized the appearance seed log label for public naming.
