refactor: upgrade to Go 1.26 and modernize code idioms

- Replace `interface{}` with `any` type alias across all packages
- Use built-in `min()`/`max()` for parameter clamping
- Use `slices.SortFunc`, `slices.Min`, `slices.Max` for cleaner code
- Use `strings.Cut()` for simpler string parsing in auth middleware
- Use `errors.Is()` for proper error comparison in handlers
- Update dependencies: golang.org/x/image 0.37.0 -> 0.38.0
- Add Wire code generation guidelines to ARCHITECTURE.md
- Disable Go cache in CI build workflow

internal/repository/post_repo.go

@@ -166,7 +166,7 @@ func (r *postRepository) UpdateWithImages(post *model.Post, images *[]string) er
 // UpdateModerationStatus 更新帖子审核状态
 func (r *postRepository) UpdateModerationStatus(postID string, status model.PostStatus, rejectReason string, reviewedBy string) error {
 	// 审核状态更新属于管理操作，不应影响帖子内容更新时间（updated_at）
-	updates := map[string]interface{}{
+	updates := map[string]any{
 		"status":        status,
 		"reviewed_at":   gorm.Expr("CURRENT_TIMESTAMP"),
 		"reviewed_by":   reviewedBy,
@@ -455,7 +455,7 @@ func (r *postRepository) IsFavoritedBatch(postIDs []string, userID string) map[s
 // IncrementViews 增加帖子观看量
 func (r *postRepository) IncrementViews(postID string) error {
 	return r.db.Model(&model.Post{}).Where("id = ?", postID).
-		UpdateColumns(map[string]interface{}{
+		UpdateColumns(map[string]any{
 			"views_count": gorm.Expr("views_count + 1"),
 			"updated_at":  gorm.Expr("updated_at"),
 		}).Error
@@ -467,7 +467,7 @@ func (r *postRepository) IncrementShares(postID string) (int, error) {
 	err := r.db.Transaction(func(tx *gorm.DB) error {
 		res := tx.Model(&model.Post{}).
 			Where("id = ? AND status = ?", postID, model.PostStatusPublished).
-			Updates(map[string]interface{}{
+			Updates(map[string]any{
 				"shares_count": gorm.Expr("shares_count + 1"),
 				"updated_at":   gorm.Expr("updated_at"),
 			})
@@ -909,11 +909,11 @@ func (r *postRepository) BatchUpdateStatus(ids []string, status model.PostStatus
 	result := r.db.Model(&model.Post{}).
 		Where("id IN ?", ids).
 		Updates(map[string]any{
-			"status":       status,
-			"reviewed_at":  gorm.Expr("CURRENT_TIMESTAMP"),
-			"reviewed_by":  reviewedBy,
+			"status":        status,
+			"reviewed_at":   gorm.Expr("CURRENT_TIMESTAMP"),
+			"reviewed_by":   reviewedBy,
 			"reject_reason": "",
-			"updated_at":   gorm.Expr("updated_at"),
+			"updated_at":    gorm.Expr("updated_at"),
 		})
 
 	if result.Error != nil {