refactor: remove persister abstraction layer

Inline persistence logic directly into game stores and handlers:
- game/persist.go: DB mapping methods on GameStore and GameInstance
- snake/persist.go: DB mapping methods on SnakeStore and SnakeGameInstance
- Chat persistence inlined into c4game handlers
- Delete db/persister.go (GamePersister, SnakePersister, ChatPersister)
- Stores now take *repository.Queries directly instead of Persister interface

features/c4game/handlers.go

@@ -1,8 +1,10 @@
 package c4game
 
 import (
+	"context"
 	"encoding/json"
 	"net/http"
+	"slices"
 	"strconv"
 	"sync"
 	"time"
@@ -10,14 +12,14 @@ import (
 	"github.com/alexedwards/scs/v2"
 	"github.com/go-chi/chi/v5"
 	"github.com/nats-io/nats.go"
-	"github.com/ryanhamamura/c4/db"
+	"github.com/ryanhamamura/c4/db/repository"
 	"github.com/ryanhamamura/c4/features/c4game/components"
 	"github.com/ryanhamamura/c4/features/c4game/pages"
 	"github.com/ryanhamamura/c4/game"
 	"github.com/starfederation/datastar-go/datastar"
 )
 
-func HandleGamePage(store *game.GameStore, sessions *scs.SessionManager, chatPersister *db.ChatPersister) http.HandlerFunc {
+func HandleGamePage(store *game.GameStore, sessions *scs.SessionManager, queries *repository.Queries) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		gameID := chi.URLParam(r, "game_id")
 
@@ -73,8 +75,8 @@ func HandleGamePage(store *game.GameStore, sessions *scs.SessionManager, chatPer
 
 		// Player is in the game — render full game page
 		g := gi.GetGame()
-		uiMsgs, _ := chatPersister.LoadChatMessages(gameID)
-		msgs := uiChatToComponents(uiMsgs)
+		chatMsgs := loadChatMessages(queries, gameID)
+		msgs := chatToComponents(chatMsgs)
 
 		if err := pages.GamePage(g, myColor, msgs).Render(r.Context(), w); err != nil {
 			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
@@ -82,7 +84,7 @@ func HandleGamePage(store *game.GameStore, sessions *scs.SessionManager, chatPer
 	}
 }
 
-func HandleGameEvents(store *game.GameStore, nc *nats.Conn, sessions *scs.SessionManager, chatPersister *db.ChatPersister) http.HandlerFunc {
+func HandleGameEvents(store *game.GameStore, nc *nats.Conn, sessions *scs.SessionManager, queries *repository.Queries) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		gameID := chi.URLParam(r, "game_id")
 
@@ -103,9 +105,9 @@ func HandleGameEvents(store *game.GameStore, nc *nats.Conn, sessions *scs.Sessio
 		sse := datastar.NewSSE(w, r)
 
 		// Load initial chat messages
-		uiMsgs, _ := chatPersister.LoadChatMessages(gameID)
+		chatMsgs := loadChatMessages(queries, gameID)
 		var chatMu sync.Mutex
-		chatMessages := uiChatToComponents(uiMsgs)
+		chatMessages := chatToComponents(chatMsgs)
 
 		// Send initial render of all components
 		sendGameComponents(sse, gi, myColor, chatMessages, &chatMu, gameID)
@@ -203,7 +205,7 @@ func HandleDropPiece(store *game.GameStore, sessions *scs.SessionManager) http.H
 	}
 }
 
-func HandleSendChat(store *game.GameStore, nc *nats.Conn, sessions *scs.SessionManager, chatPersister *db.ChatPersister) http.HandlerFunc {
+func HandleSendChat(store *game.GameStore, nc *nats.Conn, sessions *scs.SessionManager, queries *repository.Queries) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		gameID := chi.URLParam(r, "game_id")
 
@@ -254,7 +256,7 @@ func HandleSendChat(store *game.GameStore, nc *nats.Conn, sessions *scs.SessionM
 			Message:  signals.ChatMsg,
 			Time:     time.Now().UnixMilli(),
 		}
-		chatPersister.SaveChatMessage(gameID, cm)
+		saveChatMessage(queries, gameID, cm)
 
 		data, err := json.Marshal(cm)
 		if err != nil {
@@ -353,10 +355,40 @@ func sendGameComponents(sse *datastar.ServerSentEventGenerator, gi *game.GameIns
 	sse.PatchElementTempl(components.Chat(msgs, gameID), datastar.WithSelectorID("c4-chat")) //nolint:errcheck
 }
 
-// uiChatToComponents converts ui.C4ChatMessage slice to components.ChatMessage slice.
-func uiChatToComponents(uiMsgs []game.ChatMessage) []components.ChatMessage {
-	msgs := make([]components.ChatMessage, len(uiMsgs))
-	for i, m := range uiMsgs {
+// Chat persistence helpers — inlined from the former ChatPersister.
+
+func saveChatMessage(queries *repository.Queries, gameID string, msg game.ChatMessage) {
+	queries.CreateChatMessage(context.Background(), repository.CreateChatMessageParams{ //nolint:errcheck
+		GameID:    gameID,
+		Nickname:  msg.Nickname,
+		Color:     int64(msg.Color),
+		Message:   msg.Message,
+		CreatedAt: msg.Time,
+	})
+}
+
+func loadChatMessages(queries *repository.Queries, gameID string) []game.ChatMessage {
+	rows, err := queries.GetChatMessages(context.Background(), gameID)
+	if err != nil {
+		return nil
+	}
+	msgs := make([]game.ChatMessage, len(rows))
+	for i, r := range rows {
+		msgs[i] = game.ChatMessage{
+			Nickname: r.Nickname,
+			Color:    int(r.Color),
+			Message:  r.Message,
+			Time:     r.CreatedAt,
+		}
+	}
+	// DB returns newest-first; reverse for display
+	slices.Reverse(msgs)
+	return msgs
+}
+
+func chatToComponents(chatMsgs []game.ChatMessage) []components.ChatMessage {
+	msgs := make([]components.ChatMessage, len(chatMsgs))
+	for i, m := range chatMsgs {
 		msgs[i] = components.ChatMessage{
 			Nickname: m.Nickname,
 			Color:    m.Color,

features/c4game/routes.go

@@ -4,7 +4,7 @@ import (
 	"github.com/alexedwards/scs/v2"
 	"github.com/go-chi/chi/v5"
 	"github.com/nats-io/nats.go"
-	"github.com/ryanhamamura/c4/db"
+	"github.com/ryanhamamura/c4/db/repository"
 	"github.com/ryanhamamura/c4/game"
 )
 
@@ -13,14 +13,14 @@ func SetupRoutes(
 	store *game.GameStore,
 	nc *nats.Conn,
 	sessions *scs.SessionManager,
-	chatPersister *db.ChatPersister,
+	queries *repository.Queries,
 ) error {
-	router.Get("/game/{game_id}", HandleGamePage(store, sessions, chatPersister))
-	router.Get("/game/{game_id}/events", HandleGameEvents(store, nc, sessions, chatPersister))
+	router.Get("/game/{game_id}", HandleGamePage(store, sessions, queries))
+	router.Get("/game/{game_id}/events", HandleGameEvents(store, nc, sessions, queries))
 
 	router.Route("/api/game/{game_id}", func(r chi.Router) {
 		r.Post("/drop", HandleDropPiece(store, sessions))
-		r.Post("/chat", HandleSendChat(store, nc, sessions, chatPersister))
+		r.Post("/chat", HandleSendChat(store, nc, sessions, queries))
 		r.Post("/join", HandleSetNickname(store, sessions))
 		r.Post("/rematch", HandleRematch(store, sessions))
 	})