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

internal/pkg/gorse/client.go

@@ -10,16 +10,17 @@ import (
 	"time"
 
 	gorseio "github.com/gorse-io/gorse-go"
+	"go.uber.org/zap"
 )
 
 // FeedbackType 反馈类型
 type FeedbackType string
 
 const (
-	FeedbackTypeLike     FeedbackType = "like"     // 点赞
-	FeedbackTypeStar     FeedbackType = "star"     // 收藏
-	FeedbackTypeComment  FeedbackType = "comment"  // 评论
-	FeedbackTypeRead     FeedbackType = "read"     // 浏览
+	FeedbackTypeLike    FeedbackType = "like"    // 点赞
+	FeedbackTypeStar    FeedbackType = "star"    // 收藏
+	FeedbackTypeComment FeedbackType = "comment" // 评论
+	FeedbackTypeRead    FeedbackType = "read"    // 浏览
 )
 
 // Score 非个性化推荐返回的评分项
@@ -206,7 +207,10 @@ func (c *client) UpsertItemWithEmbedding(ctx context.Context, itemID string, cat
 		var err error
 		embedding, err = GetEmbedding(textToEmbed)
 		if err != nil {
-			log.Printf("[WARN] Failed to get embedding for item %s: %v, using zero vector", itemID, err)
+			zap.L().Warn("Failed to get embedding for item, using zero vector",
+				zap.String("itemID", itemID),
+				zap.Error(err),
+			)
 			embedding = make([]float64, 1024)
 		}
 	} else {

internal/pkg/gorse/embedding.go

@@ -5,9 +5,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"log"
 	"net/http"
 	"time"
+
+	"go.uber.org/zap"
 )
 
 // EmbeddingConfig embedding服务配置
@@ -94,7 +95,7 @@ func GetEmbedding(text string) ([]float64, error) {
 // InitEmbeddingWithConfig 从应用配置初始化embedding
 func InitEmbeddingWithConfig(apiKey, url, model string) {
 	if apiKey == "" {
-		log.Println("[WARN] Gorse embedding API key not set, using default")
+		zap.L().Warn("Gorse embedding API key not set, using default")
 	}
 	defaultEmbeddingConfig.APIKey = apiKey
 	if url != "" {
@@ -103,4 +104,4 @@ func InitEmbeddingWithConfig(apiKey, url, model string) {
 	if model != "" {
 		defaultEmbeddingConfig.Model = model
 	}
-}
+}