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/app.go

@@ -3,7 +3,6 @@ package main
 import (
 	"context"
 	"fmt"
-	"log"
 	"net/http"
 
 	"carrot_bbs/internal/config"
@@ -11,6 +10,7 @@ import (
 	"carrot_bbs/internal/router"
 	"carrot_bbs/internal/service"
 
+	"go.uber.org/zap"
 	"gorm.io/gorm"
 )
 
@@ -22,6 +22,7 @@ type App struct {
 	PushService service.PushService
 	GRPCServer  *runner.Server
 	Server      *http.Server
+	Logger      *zap.Logger
 }
 
 // NewApp 创建应用程序
@@ -31,6 +32,7 @@ func NewApp(
 	r *router.Router,
 	pushService service.PushService,
 	grpcServer *runner.Server,
+	logger *zap.Logger,
 ) *App {
 	return &App{
 		Config:      cfg,
@@ -38,6 +40,7 @@ func NewApp(
 		Router:      r,
 		PushService: pushService,
 		GRPCServer:  grpcServer,
+		Logger:      logger,
 	}
 }
 
@@ -45,7 +48,7 @@ func NewApp(
 func (a *App) Start(ctx context.Context) error {
 	// 1. 启动 gRPC 服务器（在 HTTP 服务器之前）
 	if a.GRPCServer != nil {
-		log.Println("Starting gRPC server...")
+		a.Logger.Info("Starting gRPC server")
 		if err := a.GRPCServer.Start(); err != nil {
 			return fmt.Errorf("failed to start gRPC server: %w", err)
 		}
@@ -56,7 +59,9 @@ func (a *App) Start(ctx context.Context) error {
 
 	// 3. 创建 HTTP 服务器
 	addr := fmt.Sprintf("%s:%d", a.Config.Server.Host, a.Config.Server.Port)
-	log.Printf("Starting HTTP server at %s", addr)
+	a.Logger.Info("Starting HTTP server",
+		zap.String("address", addr),
+	)
 
 	a.Server = &http.Server{
 		Addr:    addr,
@@ -66,7 +71,9 @@ func (a *App) Start(ctx context.Context) error {
 	// 4. 启动 HTTP 服务器
 	go func() {
 		if err := a.Server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
-			log.Fatalf("listen: %s\n", err)
+			a.Logger.Fatal("HTTP server listen error",
+				zap.Error(err),
+			)
 		}
 	}()
 
@@ -75,33 +82,35 @@ func (a *App) Start(ctx context.Context) error {
 
 // Stop 停止应用程序
 func (a *App) Stop(ctx context.Context) error {
-	log.Println("Shutting down server...")
+	a.Logger.Info("Shutting down server")
 
 	// 1. 停止 HTTP 服务器
 	if a.Server != nil {
-		log.Println("Stopping HTTP server...")
+		a.Logger.Info("Stopping HTTP server")
 		if err := a.Server.Shutdown(ctx); err != nil {
-			log.Printf("HTTP server forced to shutdown: %v", err)
+			a.Logger.Error("HTTP server forced to shutdown",
+				zap.Error(err),
+			)
 		}
 	}
 
 	// 2. 停止 gRPC 服务器
 	if a.GRPCServer != nil {
-		log.Println("Stopping gRPC server...")
+		a.Logger.Info("Stopping gRPC server")
 		a.GRPCServer.Stop()
 	}
 
 	// 3. 停止推送 Worker
-	log.Println("Stopping push worker...")
+	a.Logger.Info("Stopping push worker")
 	a.PushService.StopPushWorker()
 
 	// 4. 关闭数据库连接
-	log.Println("Closing database connection...")
+	a.Logger.Info("Closing database connection")
 	sqlDB, err := a.DB.DB()
 	if err == nil {
 		sqlDB.Close()
 	}
 
-	log.Println("Server exited")
+	a.Logger.Info("Server exited")
 	return nil
 }