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/cache/redis_cache.go

@@ -3,10 +3,10 @@ package cache
 import (
 	"context"
 	"encoding/json"
-	"log"
 	"time"
 
 	"github.com/redis/go-redis/v9"
+	"go.uber.org/zap"
 
 	redisPkg "carrot_bbs/internal/pkg/redis"
 )
@@ -32,13 +32,19 @@ func (c *RedisCache) Set(key string, value interface{}, ttl time.Duration) {
 	data, err := json.Marshal(value)
 	if err != nil {
 		recordSetError()
-		log.Printf("[RedisCache] Failed to marshal value for key %s: %v", key, err)
+		zap.L().Error("Failed to marshal value for key",
+			zap.String("key", key),
+			zap.Error(err),
+		)
 		return
 	}
 
 	if err := c.client.Set(c.ctx, key, data, ttl); err != nil {
 		recordSetError()
-		log.Printf("[RedisCache] Failed to set key %s: %v", key, err)
+		zap.L().Error("Failed to set key",
+			zap.String("key", key),
+			zap.Error(err),
+		)
 	}
 }
 
@@ -50,7 +56,10 @@ func (c *RedisCache) Get(key string) (interface{}, bool) {
 		if err == redis.Nil {
 			return nil, false
 		}
-		log.Printf("[RedisCache] Failed to get key %s: %v", key, err)
+		zap.L().Error("Failed to get key",
+			zap.String("key", key),
+			zap.Error(err),
+		)
 		return nil, false
 	}
 
@@ -63,7 +72,10 @@ func (c *RedisCache) Delete(key string) {
 	key = normalizeKey(key)
 	recordInvalidate()
 	if err := c.client.Del(c.ctx, key); err != nil {
-		log.Printf("[RedisCache] Failed to delete key %s: %v", key, err)
+		zap.L().Error("Failed to delete key",
+			zap.String("key", key),
+			zap.Error(err),
+		)
 	}
 }
 
@@ -76,14 +88,20 @@ func (c *RedisCache) DeleteByPrefix(prefix string) {
 	for {
 		keys, nextCursor, err := rdb.Scan(c.ctx, cursor, prefix+"*", 100).Result()
 		if err != nil {
-			log.Printf("[RedisCache] Failed to scan keys with prefix %s: %v", prefix, err)
+			zap.L().Error("Failed to scan keys with prefix",
+				zap.String("prefix", prefix),
+				zap.Error(err),
+			)
 			return
 		}
 
 		if len(keys) > 0 {
 			recordInvalidateMultiple(int64(len(keys)))
 			if err := c.client.Del(c.ctx, keys...); err != nil {
-				log.Printf("[RedisCache] Failed to delete keys with prefix %s: %v", prefix, err)
+				zap.L().Error("Failed to delete keys with prefix",
+					zap.String("prefix", prefix),
+					zap.Error(err),
+				)
 			}
 		}
 
@@ -97,13 +115,15 @@ func (c *RedisCache) DeleteByPrefix(prefix string) {
 // Clear 清空所有缓存
 func (c *RedisCache) Clear() {
 	if settings.DisableFlushDB {
-		log.Printf("[RedisCache] Skip FlushDB because cache.disable_flushdb=true")
+		zap.L().Debug("Skip FlushDB because cache.disable_flushdb=true")
 		return
 	}
 	recordInvalidate()
 	rdb := c.client.GetClient()
 	if err := rdb.FlushDB(c.ctx).Err(); err != nil {
-		log.Printf("[RedisCache] Failed to clear cache: %v", err)
+		zap.L().Error("Failed to clear cache",
+			zap.Error(err),
+		)
 	}
 }
 
@@ -112,7 +132,10 @@ func (c *RedisCache) Exists(key string) bool {
 	key = normalizeKey(key)
 	n, err := c.client.Exists(c.ctx, key)
 	if err != nil {
-		log.Printf("[RedisCache] Failed to check existence of key %s: %v", key, err)
+		zap.L().Error("Failed to check existence of key",
+			zap.String("key", key),
+			zap.Error(err),
+		)
 		return false
 	}
 	return n > 0
@@ -129,7 +152,10 @@ func (c *RedisCache) IncrementBy(key string, value int64) int64 {
 	rdb := c.client.GetClient()
 	result, err := rdb.IncrBy(c.ctx, key, value).Result()
 	if err != nil {
-		log.Printf("[RedisCache] Failed to increment key %s: %v", key, err)
+		zap.L().Error("Failed to increment key",
+			zap.String("key", key),
+			zap.Error(err),
+		)
 		return 0
 	}
 	return result