feat: 实现内容系统 MVC（Post CRUD + 审核流转）

按 content-system.md 设计文档，实现帖子内容系统的最小可行 MVC。

新增：
- Model: Post 模型，含 5 种状态（draft/pending/approved/rejected/locked）
- Repository: post_repo.go，分页查询（前台 approved 列表 + 后台全状态筛选）
- Service: post_service.go，核心业务逻辑（状态流转、Markdown 渲染 Goldmark）
- Controller: post_controller + admin_post_controller，SSR 页面 6 个 + API 13 个
- Template: 列表/详情/编辑器/404 + 管理员列表，各配 CSS/JS
- 路由: /posts, /posts/:id, /posts/new, /posts/:id/edit, REST API, Admin API
- gomod: + github.com/yuin/goldmark v1.8.2

修改：
- Main: AutoMigrate Post 表
- Router: deps 注册 PostService/Controller，路由注册
- Nav: 新增“帖子”导航链接
- Admin Sidebar: 新增“内容管理”入口

设计：
- 审核开关复用 audit.enabled，开启时帖子为 draft，关闭后直接 approved
- 仅 approved 公开可见，作者/admin 可预览非公开状态帖子
- 严格分层 ISP 接口: Controller → postUseCase, Service → postStore, Repo → *PostRepo
- 状态保护: pending/locked 禁止编辑，rejected 编辑后自动重置为 draft

internal/router/admin.go

@@ -25,6 +25,7 @@ func setupAdminRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
 			middleware.RequirePageRole(model.RoleAdmin))
 		adminPages.GET("/audits", d.auditCtrl.AuditPage,
 			middleware.RequirePageRole(model.RoleAdmin))
+		adminPages.GET("/posts", d.adminPostCtrl.PostsPage)
 		adminPages.GET("/site-settings", d.siteSettingCtrl.SiteSettingsPage,
 			middleware.RequirePageRole(model.RoleOwner))
 	}
@@ -54,4 +55,17 @@ func setupAdminRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
 		siteSettingsAPI.PUT("/bool", d.siteSettingCtrl.UpdateBoolSetting)
 		siteSettingsAPI.GET("/bool", d.siteSettingCtrl.GetBoolSetting)
 	}
+
+	// --- 帖子管理 API（admin+） ---
+	adminPostAPI := r.Group("/api/admin/posts")
+	adminPostAPI.Use(d.authMdw.Required())
+	adminPostAPI.Use(middleware.RequireMinRole(model.RoleAdmin))
+	adminPostAPI.Use(middleware.CSRF(cfg))
+	{
+		adminPostAPI.POST("/:id/approve", d.adminPostCtrl.Approve)
+		adminPostAPI.POST("/:id/reject", d.adminPostCtrl.Reject)
+		adminPostAPI.POST("/:id/lock", d.adminPostCtrl.Lock)
+		adminPostAPI.POST("/:id/unlock", d.adminPostCtrl.Unlock)
+		adminPostAPI.POST("/:id/restore", d.adminPostCtrl.Restore)
+	}
 }

internal/router/api.go

@@ -41,5 +41,21 @@ func setupAPIRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
 		api.POST("/auth/confirm-restore", d.tokenCtrl.ConfirmRestore)
 		api.POST("/auth/logout", d.tokenCtrl.Logout)
 		api.POST("/auth/refresh", d.tokenCtrl.RefreshToken)
+
+		// 帖子公开 API（无需登录）
+		api.GET("/posts", d.postCtrl.ListAPI)
+		api.GET("/posts/:id", d.postCtrl.ShowAPI)
+	}
+
+	// --- 帖子 API（需登录） ---
+	postsAPI := r.Group("/api/posts")
+	postsAPI.Use(d.authMdw.Required())
+	postsAPI.Use(middleware.CSRF(cfg))
+	{
+		postsAPI.POST("", d.postCtrl.Create)
+		postsAPI.PUT("/:id", d.postCtrl.Update)
+		postsAPI.DELETE("/:id", d.postCtrl.Delete)
+		postsAPI.POST("/:id/submit", d.postCtrl.Submit)
+		postsAPI.POST("/preview", d.postCtrl.PreviewAPI)
 	}
 }

internal/router/deps_core.go

@@ -16,6 +16,8 @@ type dependencies struct {
 	authMdw         *middleware.AuthMiddleware
 	settingsCtrl    *controller.SettingsController
 	messageCtrl     *controller.MessageController
+	postCtrl        *controller.PostController
+	adminPostCtrl   *adminCtrl.AdminPostController
 	adminCtrl       *adminCtrl.AdminController
 	auditCtrl       *adminCtrl.AuditController
 	siteSettingCtrl *adminCtrl.SiteSettingController

internal/router/deps_extra.go

@@ -30,9 +30,15 @@ func buildDeps(db *gorm.DB, cfg *config.Config, siteSettings *config.SiteSetting
 		},
 	)
 
+	postRepo := repository.NewPostRepo(db)
+	postService := service.NewPostService(postRepo, siteSettings)
+	postCtrl := controller.NewPostController(postService)
+	adminPostCtrl := adminCtrl.NewAdminPostController(postService)
+
 	return &dependencies{
 		authCtrl: authCtrl, authMdw: authMdw, settingsCtrl: settingsCtrl,
-		messageCtrl: messageController, adminCtrl: adminController,
-		auditCtrl: auditController, siteSettingCtrl: siteSettingController, tokenCtrl: authCtrl,
+		messageCtrl: messageController, postCtrl: postCtrl, adminPostCtrl: adminPostCtrl,
+		adminCtrl: adminController, auditCtrl: auditController,
+		siteSettingCtrl: siteSettingController, tokenCtrl: authCtrl,
 	}
 }

internal/router/frontend.go

@@ -33,6 +33,18 @@ func setupFrontendRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
 		})
 		pages.GET("/settings/:tab", d.settingsCtrl.SettingsPage)
 		pages.GET("/messages", d.messageCtrl.MessagesPage)
+
+		// 帖子页面
+		pages.GET("/posts", d.postCtrl.ListPage)
+		pages.GET("/posts/:id", d.postCtrl.ShowPage)
+	}
+
+	// 帖子页面（需登录）
+	postPages := r.Group("/posts")
+	postPages.Use(d.authMdw.Required())
+	{
+		postPages.GET("/new", d.postCtrl.NewPage)
+		postPages.GET("/:id/edit", d.postCtrl.EditPage)
 	}
 
 	// 认证页面（已登录自动跳走）