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/i18n/en.ts

@@ -6,6 +6,11 @@ export const en = {
   'app.title': 'Scrabble',
   'connection.connecting': 'Connecting…',
 
+  'blocked.title': 'Account blocked',
+  'blocked.permanent': 'Your account is blocked.',
+  'blocked.temporary': 'Your account is blocked until {until}.',
+  'blocked.reason': 'Reason:',
+
   'common.back': 'Back',
   'common.cancel': 'Cancel',
   'common.ok': 'OK',