feat(admin): manual account blocking (suspensions)

Operator-driven hard block, the counterpart to the soft high-rate flag: permanent or until a date, with an optional reason chosen from an editable en+ru picklist (snapshotted onto the block). A block forfeits the player's active games (opponent wins, as a resignation) and cancels their open matchmaking games. A backend gate refuses a blocked account on every /api/v1/user/* route except the block-status probe with 403 account_blocked, which threads through the gateway as the Execute result_code; the UI surfaces it as a terminal blocked screen and stops all push/poll. Temporary blocks self-expire; the operator can unblock at any time (lost games stay lost). Sessions are not revoked, so the blocked client can still reach the exempt block-status endpoint.

Backend: migration 00003 (account_suspensions + suspension_reasons) + jet regen; account suspension store; game.ForfeitAllForAccount; requireNotSuspended gate + block-status endpoint; admin console block/unblock + Reasons CRUD. Wire: fbs BlockStatus + account.block_status gateway op. UI: blocked screen, app state, transport/codec, i18n. Docs: ARCHITECTURE, FUNCTIONAL(+ru), PRERELEASE (AB).

ui/src/lib/codec.ts

@@ -9,6 +9,7 @@ import { indexForLetter, letterForIndex, setAlphabet, type AlphabetEntryWire } f
 import type { PlacedTile } from './client';
 import type {
   AccountRef,
+  BlockStatus,
   ChatMessage,
   EvalResult,
   FriendCode,
@@ -314,6 +315,16 @@ export function decodeProfile(buf: Uint8Array): Profile {
   };
 }
 
+export function decodeBlockStatus(buf: Uint8Array): BlockStatus {
+  const b = fb.BlockStatus.getRootAsBlockStatus(new ByteBuffer(buf));
+  return {
+    blocked: b.blocked(),
+    permanent: b.permanent(),
+    until: s(b.until()),
+    reason: s(b.reason()),
+  };
+}
+
 // decodeStateViewTable projects a StateView table (a root or one nested in an event) to the
 // model. It caches the alphabet when present (a per-variant cache miss) and decodes the index
 // rack to display letters with it.