Stage 7 (wip): wire remaining ops (backend REST, FBS, gateway transcode) + real UI transport

backend: REST handlers for pass/exchange/resign/hint/evaluate/check_word/complaint/history/chat-list/nudge + new game.ListForAccount (my games) + seat display_name resolution
pkg/fbs: GameActionRequest/ExchangeRequest/EvalRequest/EvalResult/CheckWordRequest/WordCheckResult/ComplaintRequest/HintResult/History/GameList/ChatList + SeatView.display_name; committed Go regenerated (flatc 23.5.26)
gateway: 11 new transcode ops + backendclient methods + FB encoders
ui: edge TS codegen (flatc --ts + protoc-gen-es, committed), FlatBuffers<->model codec, real connect-web transport (binary, bearer auth, Subscribe). prod bundle ~69KB gzip JS

pkg/fbs/scrabble.fbs

@@ -23,13 +23,15 @@ table TileRecord {
   blank:bool;
 }
 
-// SeatView is one seat's public standing in a game.
+// SeatView is one seat's public standing in a game. display_name is resolved by the
+// backend from the account store (added trailing — backward-compatible).
 table SeatView {
   seat:int;
   account_id:string;
   score:int;
   hints_used:int;
   is_winner:bool;
+  display_name:string;
 }
 
 // GameView is the shared (non-private) game summary.
@@ -143,6 +145,67 @@ table StateView {
   hints_remaining:int;
 }
 
+// GameActionRequest carries just a game id (pass / resign / hint / history).
+table GameActionRequest {
+  game_id:string;
+}
+
+// ExchangeRequest swaps the listed rack tiles back into the bag.
+table ExchangeRequest {
+  game_id:string;
+  tiles:[string];
+}
+
+// EvalRequest previews a tentative play without committing it.
+table EvalRequest {
+  game_id:string;
+  dir:string;
+  tiles:[TileRecord];
+}
+
+// EvalResult is an unlimited move preview: legality, score and the words formed.
+table EvalResult {
+  legal:bool;
+  score:int;
+  words:[string];
+}
+
+// CheckWordRequest looks a word up in the game's pinned dictionary.
+table CheckWordRequest {
+  game_id:string;
+  word:string;
+}
+
+// WordCheckResult is the dictionary lookup outcome.
+table WordCheckResult {
+  word:string;
+  legal:bool;
+}
+
+// ComplaintRequest disputes a word-check result.
+table ComplaintRequest {
+  game_id:string;
+  word:string;
+  note:string;
+}
+
+// HintResult is the top-ranked move plus the remaining hint budget.
+table HintResult {
+  move:MoveRecord;
+  hints_remaining:int;
+}
+
+// History is a game's decoded move journal — the source for client board replay.
+table History {
+  game_id:string;
+  moves:[MoveRecord];
+}
+
+// GameList is the caller's games (active and finished) for the lobby.
+table GameList {
+  games:[GameView];
+}
+
 // --- lobby (authenticated) ---
 
 // EnqueueRequest joins the per-variant auto-match pool.
@@ -174,6 +237,11 @@ table ChatMessage {
   created_at_unix:long;
 }
 
+// ChatList is a game's chat history.
+table ChatList {
+  messages:[ChatMessage];
+}
+
 // --- push event payloads ---
 
 // YourTurnEvent signals that it is now the recipient's turn.