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

gateway/internal/transcode/encode.go

@@ -100,9 +100,8 @@ func encodeMatch(m backendclient.MatchResp) []byte {
 	return b.FinishedBytes()
 }
 
-// encodeChat builds a ChatMessage payload.
-func encodeChat(c backendclient.ChatResp) []byte {
-	b := flatbuffers.NewBuilder(192)
+// buildChatMessage builds a ChatMessage table and returns its offset.
+func buildChatMessage(b *flatbuffers.Builder, c backendclient.ChatResp) flatbuffers.UOffsetT {
 	id := b.CreateString(c.ID)
 	gid := b.CreateString(c.GameID)
 	sid := b.CreateString(c.SenderID)
@@ -115,7 +114,103 @@ func encodeChat(c backendclient.ChatResp) []byte {
 	fb.ChatMessageAddKind(b, kind)
 	fb.ChatMessageAddBody(b, body)
 	fb.ChatMessageAddCreatedAtUnix(b, c.CreatedAtUnix)
-	b.Finish(fb.ChatMessageEnd(b))
+	return fb.ChatMessageEnd(b)
+}
+
+// encodeChat builds a ChatMessage payload.
+func encodeChat(c backendclient.ChatResp) []byte {
+	b := flatbuffers.NewBuilder(192)
+	b.Finish(buildChatMessage(b, c))
+	return b.FinishedBytes()
+}
+
+// encodeHintResult builds a HintResult payload.
+func encodeHintResult(r backendclient.HintResultResp) []byte {
+	b := flatbuffers.NewBuilder(512)
+	move := buildMoveRecord(b, r.Move)
+	fb.HintResultStart(b)
+	fb.HintResultAddMove(b, move)
+	fb.HintResultAddHintsRemaining(b, int32(r.HintsRemaining))
+	b.Finish(fb.HintResultEnd(b))
+	return b.FinishedBytes()
+}
+
+// encodeEvalResult builds an EvalResult payload.
+func encodeEvalResult(r backendclient.EvalResultResp) []byte {
+	b := flatbuffers.NewBuilder(256)
+	words := buildStringVector(b, r.Words, fb.EvalResultStartWordsVector)
+	fb.EvalResultStart(b)
+	fb.EvalResultAddLegal(b, r.Legal)
+	fb.EvalResultAddScore(b, int32(r.Score))
+	fb.EvalResultAddWords(b, words)
+	b.Finish(fb.EvalResultEnd(b))
+	return b.FinishedBytes()
+}
+
+// encodeWordCheck builds a WordCheckResult payload.
+func encodeWordCheck(r backendclient.WordCheckResp) []byte {
+	b := flatbuffers.NewBuilder(64)
+	word := b.CreateString(r.Word)
+	fb.WordCheckResultStart(b)
+	fb.WordCheckResultAddWord(b, word)
+	fb.WordCheckResultAddLegal(b, r.Legal)
+	b.Finish(fb.WordCheckResultEnd(b))
+	return b.FinishedBytes()
+}
+
+// encodeHistory builds a History payload (the decoded move journal).
+func encodeHistory(r backendclient.HistoryResp) []byte {
+	b := flatbuffers.NewBuilder(1024)
+	moveOffs := make([]flatbuffers.UOffsetT, len(r.Moves))
+	for i, m := range r.Moves {
+		moveOffs[i] = buildMoveRecord(b, m)
+	}
+	fb.HistoryStartMovesVector(b, len(moveOffs))
+	for i := len(moveOffs) - 1; i >= 0; i-- {
+		b.PrependUOffsetT(moveOffs[i])
+	}
+	moves := b.EndVector(len(moveOffs))
+	gid := b.CreateString(r.GameID)
+	fb.HistoryStart(b)
+	fb.HistoryAddGameId(b, gid)
+	fb.HistoryAddMoves(b, moves)
+	b.Finish(fb.HistoryEnd(b))
+	return b.FinishedBytes()
+}
+
+// encodeGameList builds a GameList payload (the caller's games).
+func encodeGameList(r backendclient.GameListResp) []byte {
+	b := flatbuffers.NewBuilder(1024)
+	gameOffs := make([]flatbuffers.UOffsetT, len(r.Games))
+	for i, g := range r.Games {
+		gameOffs[i] = buildGameView(b, g)
+	}
+	fb.GameListStartGamesVector(b, len(gameOffs))
+	for i := len(gameOffs) - 1; i >= 0; i-- {
+		b.PrependUOffsetT(gameOffs[i])
+	}
+	games := b.EndVector(len(gameOffs))
+	fb.GameListStart(b)
+	fb.GameListAddGames(b, games)
+	b.Finish(fb.GameListEnd(b))
+	return b.FinishedBytes()
+}
+
+// encodeChatList builds a ChatList payload (a game's chat history).
+func encodeChatList(r backendclient.ChatListResp) []byte {
+	b := flatbuffers.NewBuilder(512)
+	msgOffs := make([]flatbuffers.UOffsetT, len(r.Messages))
+	for i, m := range r.Messages {
+		msgOffs[i] = buildChatMessage(b, m)
+	}
+	fb.ChatListStartMessagesVector(b, len(msgOffs))
+	for i := len(msgOffs) - 1; i >= 0; i-- {
+		b.PrependUOffsetT(msgOffs[i])
+	}
+	msgs := b.EndVector(len(msgOffs))
+	fb.ChatListStart(b)
+	fb.ChatListAddMessages(b, msgs)
+	b.Finish(fb.ChatListEnd(b))
 	return b.FinishedBytes()
 }
 
@@ -124,12 +219,14 @@ func buildGameView(b *flatbuffers.Builder, g backendclient.GameResp) flatbuffers
 	seatOffs := make([]flatbuffers.UOffsetT, len(g.Seats))
 	for i, s := range g.Seats {
 		aid := b.CreateString(s.AccountID)
+		dname := b.CreateString(s.DisplayName)
 		fb.SeatViewStart(b)
 		fb.SeatViewAddSeat(b, int32(s.Seat))
 		fb.SeatViewAddAccountId(b, aid)
 		fb.SeatViewAddScore(b, int32(s.Score))
 		fb.SeatViewAddHintsUsed(b, int32(s.HintsUsed))
 		fb.SeatViewAddIsWinner(b, s.IsWinner)
+		fb.SeatViewAddDisplayName(b, dname)
 		seatOffs[i] = fb.SeatViewEnd(b)
 	}
 	fb.GameViewStartSeatsVector(b, len(seatOffs))