feat(config): add sensitive word filtering system with database support

Implement sensitive word filtering feature with configurable database and Redis
support. Add security enhancements including WebSocket origin validation, improved
password strength requirements, timing attack prevention, and production JWT secret
validation. Add batch operation validation limits and optimize user blocking
queries with subqueries.

BREAKING CHANGE: Password validation now requires minimum 8 characters with uppercase,
lowercase, and digit (was 6-50 characters without complexity requirements)

internal/model/post.go

@@ -20,11 +20,11 @@ const (
 
 // Post 帖子实体
 type Post struct {
-	ID          string `json:"id" gorm:"type:varchar(36);primaryKey"`
-	UserID      string `json:"user_id" gorm:"type:varchar(36);index;index:idx_posts_user_status_created,priority:1;not null"`
+	ID        string  `json:"id" gorm:"type:varchar(36);primaryKey"`
+	UserID    string  `json:"user_id" gorm:"type:varchar(36);index;index:idx_posts_user_status_created,priority:1;not null"`
 	ChannelID *string `json:"channel_id,omitempty" gorm:"type:varchar(36);index"`
-	Title       string `json:"title" gorm:"type:varchar(200);not null"`
-	Content     string `json:"content" gorm:"type:text;not null"`
+	Title     string  `json:"title" gorm:"type:varchar(200);not null"`
+	Content   string  `json:"content" gorm:"type:text;not null"`
 
 	// 关联
 	// User 需要参与缓存序列化；否则列表命中缓存后会丢失作者信息，前端退化为“匿名用户”
@@ -38,11 +38,11 @@ type Post struct {
 	RejectReason string     `json:"reject_reason" gorm:"type:varchar(500)"`
 
 	// 统计
-	LikesCount     int     `json:"likes_count" gorm:"column:likes_count;default:0"`
-	CommentsCount  int     `json:"comments_count" gorm:"column:comments_count;default:0"`
-	FavoritesCount int     `json:"favorites_count" gorm:"column:favorites_count;default:0"`
-	SharesCount    int     `json:"shares_count" gorm:"column:shares_count;default:0"`
-	ViewsCount     int     `json:"views_count" gorm:"column:views_count;default:0"`
+	LikesCount     int `json:"likes_count" gorm:"column:likes_count;default:0"`
+	CommentsCount  int `json:"comments_count" gorm:"column:comments_count;default:0"`
+	FavoritesCount int `json:"favorites_count" gorm:"column:favorites_count;default:0"`
+	SharesCount    int `json:"shares_count" gorm:"column:shares_count;default:0"`
+	ViewsCount     int `json:"views_count" gorm:"column:views_count;default:0"`
 
 	// 置顶/锁定
 	IsPinned   bool `json:"is_pinned" gorm:"default:false"`
@@ -78,7 +78,7 @@ func (Post) TableName() string {
 // PostImage 帖子图片
 type PostImage struct {
 	ID              string    `json:"id" gorm:"type:varchar(36);primaryKey"`
-	PostID          string    `json:"post_id" gorm:"type:varchar(36);index;not null"`
+	PostID          string    `json:"post_id" gorm:"type:varchar(36);not null;index:idx_post_images_post_sort,priority:1"`
 	URL             string    `json:"url" gorm:"type:text;not null"`
 	ThumbnailURL    string    `json:"thumbnail_url" gorm:"type:text"`
 	PreviewURL      string    `json:"preview_url" gorm:"type:text"`       // 列表/网格预览图（最大300px）
@@ -87,7 +87,7 @@ type PostImage struct {
 	Height          int       `json:"height" gorm:"default:0"`
 	Size            int64     `json:"size" gorm:"default:0"` // 文件大小（字节）
 	MimeType        string    `json:"mime_type" gorm:"type:varchar(50)"`
-	SortOrder       int       `json:"sort_order" gorm:"default:0"`
+	SortOrder       int       `json:"sort_order" gorm:"default:0;index:idx_post_images_post_sort,priority:2"`
 	CreatedAt       time.Time `json:"created_at" gorm:"autoCreateTime"`
 }