feat(posts): add post reference/internal linking functionality

Add support for referencing other posts within messages through a new post_ref segment type. Includes new PostReference model to track relationships, PostRefService for processing references, and new endpoints for post suggestions, related posts, and reference click tracking.

internal/router/router.go

@@ -272,6 +272,7 @@ func (r *Router) setupRoutes() {
 			// 使用 OptionalAuth 中间件来获取用户登录状态
 			posts.GET("", middleware.OptionalAuth(r.jwtService), r.postHandler.List)
 			posts.GET("/search", middleware.OptionalAuth(r.jwtService), r.postHandler.Search)
+			posts.GET("/suggest", middleware.OptionalAuth(r.jwtService), r.postHandler.Suggest)
 			posts.GET("/:id", middleware.OptionalAuth(r.jwtService), r.postHandler.GetByID)
 			posts.POST("", authMiddleware, middleware.RequireVerified(r.userRepo), r.postHandler.Create)
 			posts.PUT("/:id", authMiddleware, middleware.RequireVerified(r.userRepo), r.postHandler.Update)
@@ -282,6 +283,12 @@ func (r *Router) setupRoutes() {
 			// 分享计数（可选认证；仅已发布帖子生效）
 			posts.POST("/:id/share", middleware.OptionalAuth(r.jwtService), r.postHandler.RecordShare)
 
+			// 内链相关路由
+			posts.GET("/:id/related", middleware.OptionalAuth(r.jwtService), r.postHandler.GetRelatedPosts)
+			posts.GET("/:id/refs", middleware.OptionalAuth(r.jwtService), r.postHandler.GetReferencedPosts)
+			posts.GET("/suggest", middleware.OptionalAuth(r.jwtService), r.postHandler.Suggest)
+			posts.POST("/:id/ref-click", middleware.OptionalAuth(r.jwtService), r.postHandler.RecordRefClick)
+
 			// 点赞
 			posts.POST("/:id/like", authMiddleware, middleware.RequireVerified(r.userRepo), r.postHandler.Like)
 			posts.DELETE("/:id/like", authMiddleware, middleware.RequireVerified(r.userRepo), r.postHandler.Unlike)