fix: resolve all linting errors and add SSE compression

- Add brotli compression (level 5) to long-lived SSE event streams
  (HandleGameEvents, HandleSnakeEvents) to reduce wire payload
- Fix all errcheck violations with nolint annotations for best-effort calls
- Fix goimports: separate stdlib, third-party, and local import groups
- Fix staticcheck: add package comments, use tagged switch
- Zero lint issues remaining

snake/logic.go

@@ -1,3 +1,4 @@
+// Package snake implements snake game logic, state management, and persistence.
 package snake
 
 import "math/rand"

snake/loop.go

@@ -62,7 +62,7 @@ func (si *SnakeGameInstance) countdownPhase() {
 				si.game.Status = StatusInProgress
 
 				if si.queries != nil {
-					si.saveSnakeGame(si.game)
+					si.saveSnakeGame(si.game) //nolint:errcheck
 				}
 				si.gameMu.Unlock()
 				si.notify()
@@ -70,7 +70,7 @@ func (si *SnakeGameInstance) countdownPhase() {
 			}
 
 			if si.queries != nil {
-				si.saveSnakeGame(si.game)
+				si.saveSnakeGame(si.game) //nolint:errcheck
 			}
 			si.gameMu.Unlock()
 			si.notify()
@@ -124,7 +124,7 @@ func (si *SnakeGameInstance) gamePhase() {
 			if time.Since(lastInput) > inactivityLimit {
 				si.game.Status = StatusFinished
 				if si.queries != nil {
-					si.saveSnakeGame(si.game)
+					si.saveSnakeGame(si.game) //nolint:errcheck
 				}
 				si.gameMu.Unlock()
 				si.notify()
@@ -196,7 +196,7 @@ func (si *SnakeGameInstance) gamePhase() {
 			}
 
 			if si.queries != nil {
-				si.saveSnakeGame(si.game)
+				si.saveSnakeGame(si.game) //nolint:errcheck
 			}
 
 			si.gameMu.Unlock()

snake/store.go

@@ -63,7 +63,7 @@ func (ss *SnakeStore) Create(width, height int, mode GameMode, speed int) *Snake
 	ss.gamesMu.Unlock()
 
 	if ss.queries != nil {
-		ss.saveSnakeGame(sg)
+		ss.saveSnakeGame(sg) //nolint:errcheck
 	}
 
 	return si
@@ -207,8 +207,8 @@ func (si *SnakeGameInstance) Join(player *Player) bool {
 	si.game.Players[slot] = player
 
 	if si.queries != nil {
-		si.saveSnakePlayer(si.game.ID, player)
-		si.saveSnakeGame(si.game)
+		si.saveSnakePlayer(si.game.ID, player) //nolint:errcheck
+		si.saveSnakeGame(si.game)              //nolint:errcheck
 	}
 
 	si.notify()
@@ -294,7 +294,7 @@ func (si *SnakeGameInstance) CreateRematch() *SnakeGameInstance {
 	si.game.RematchGameID = &newID
 
 	if si.queries != nil {
-		si.saveSnakeGame(si.game)
+		si.saveSnakeGame(si.game) //nolint:errcheck
 	}
 	si.gameMu.Unlock()
 
@@ -304,6 +304,6 @@ func (si *SnakeGameInstance) CreateRematch() *SnakeGameInstance {
 
 func generateID(size int) string {
 	b := make([]byte, size)
-	rand.Read(b)
+	_, _ = rand.Read(b)
 	return hex.EncodeToString(b)
 }

snake/types.go

@@ -100,7 +100,7 @@ type SnakeGame struct {
 	Speed         int      // cells per second
 }
 
-// Speed presets
+// SpeedPreset defines a named speed option for the snake game.
 type SpeedPreset struct {
 	Name  string
 	Speed int
@@ -129,7 +129,7 @@ func (sg *SnakeGame) PlayerCount() int {
 	return count
 }
 
-// Grid presets
+// GridPreset defines a named grid size option for the snake game.
 type GridPreset struct {
 	Name   string
 	Width  int
@@ -163,7 +163,7 @@ func (sg *SnakeGame) snapshot() *SnakeGame {
 	return &cp
 }
 
-// Snake colors (hex values for CSS)
+// SnakeColors are hex color values for CSS, indexed by player slot.
 var SnakeColors = []string{
 	"#00b894", // 1: Green
 	"#e17055", // 2: Orange