refactor: replace standard log with zap logger and optimize code patterns

- Migrate all log.Printf/log.Println calls to structured zap logging
- Use cmp.Or for cleaner default value handling
- Replace manual loops with slices.ContainsFunc/IndexFunc
- Add batch query methods (IsLikedBatch, IsFavoritedBatch) to solve N+1 problem
- Update JSON tags from omitempty to omitzero for numeric fields
- Use errgroup-style wg.Go for worker goroutines
- Remove duplicate casbin/v2 dependency (keeping v3)
- Add plans/ to gitignore

cmd/server/main.go

@@ -2,24 +2,29 @@ package main
 
 import (
 	"context"
-	"log"
 	"os"
 	"os/signal"
 	"syscall"
 	"time"
+
+	"go.uber.org/zap"
 )
 
 func main() {
 	// 初始化应用程序（Wire 自动生成）
 	app, err := InitializeApp()
 	if err != nil {
-		log.Fatalf("failed to initialize app: %v", err)
+		zap.L().Fatal("failed to initialize app",
+			zap.Error(err),
+		)
 	}
 
 	// 启动应用程序
 	ctx := context.Background()
 	if err := app.Start(ctx); err != nil {
-		log.Fatalf("failed to start app: %v", err)
+		app.Logger.Fatal("failed to start app",
+			zap.Error(err),
+		)
 	}
 
 	// 优雅关闭
@@ -31,6 +36,8 @@ func main() {
 	defer cancel()
 
 	if err := app.Stop(shutdownCtx); err != nil {
-		log.Printf("Error during shutdown: %v", err)
+		app.Logger.Error("Error during shutdown",
+			zap.Error(err),
+		)
 	}
 }