feat: 分类系统 + 标签系统 — Phase 4 完成

分类：Model/Repo/Service/Controller + 管理后台树形页面 + 首页导航栏
标签：Model/Repo/Service/Controller + /tags/{slug} 落地页 + 写文章页输入
Post 加 CategoryID，Create/Update 支持分类和标签
SQL 迁移含 categories/tags/post_tags 表及预设未分类

internal/router/admin.go

@@ -33,6 +33,7 @@ func setupAdminRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
 		adminPages.GET("/energy/fund-logs", d.adminEnergyCtrl.FundLogPage)
 		adminPages.GET("/comments", d.adminCommentCtrl.CommentsPage)
 		adminPages.GET("/announcements", d.announcementCtrl.Page)
+		adminPages.GET("/categories", d.categoryCtrl.Page)
 	}
 
 	// --- 管理后台 API ---
@@ -115,4 +116,17 @@ func setupAdminRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
 		announcementAPI.PUT("/:id", d.announcementCtrl.Update)
 		announcementAPI.DELETE("/:id", d.announcementCtrl.Delete)
 	}
+
+	// --- 分类管理 API（moderator+） ---
+	categoryAPI := r.Group("/api/admin/categories")
+	categoryAPI.Use(d.authMdw.Required())
+	categoryAPI.Use(middleware.RequireMinRole(model.RoleModerator))
+	categoryAPI.Use(d.authMdw.BannedWriteGuard())
+	categoryAPI.Use(middleware.CSRF(cfg))
+	{
+		categoryAPI.GET("", d.categoryCtrl.List)
+		categoryAPI.POST("", d.categoryCtrl.Create)
+		categoryAPI.PUT("/:id", d.categoryCtrl.Update)
+		categoryAPI.DELETE("/:id", d.categoryCtrl.Delete)
+	}
 }

internal/router/deps_core.go

@@ -47,6 +47,10 @@ type dependencies struct {
 	homeCache         *cache.HomePageCache
 	announcementService *service.AnnouncementService
 	announcementCtrl    *adminCtrl.AnnouncementController
+	categoryCtrl        *adminCtrl.CategoryController
+	categoryService     *service.CategoryService
+	tagCtrl             *controller.TagController
+	tagService          *service.TagService
 }
 
 func buildDepsCore(db *gorm.DB, cfg *config.Config, siteSettings *config.SiteSettings, redisClient *redis.Client) (

internal/router/deps_extra.go

@@ -103,6 +103,18 @@ func buildDeps(db *gorm.DB, cfg *config.Config, siteSettings *config.SiteSetting
 
 	maintenanceMdw := middleware.NewMaintenanceMiddleware(cfg, siteSettings, sessionMgr)
 
+	// 分类系统
+	categoryRepo := repository.NewCategoryRepo(db)
+	categoryService := service.NewCategoryService(categoryRepo)
+	categoryCtrl := adminCtrl.NewCategoryController(categoryService)
+	studioCtrl.WithCategoryService(categoryService)
+
+	// 标签系统
+	tagRepo := repository.NewTagRepo(db)
+	tagService := service.NewTagService(tagRepo)
+	tagCtrl := controller.NewTagController(tagService)
+	studioCtrl.WithTagService(tagService)
+
 	// 公告系统
 	announcementRepo := repository.NewAnnouncementRepo(db)
 	announcementService := service.NewAnnouncementService(announcementRepo)
@@ -135,5 +147,9 @@ func buildDeps(db *gorm.DB, cfg *config.Config, siteSettings *config.SiteSetting
 		homeCache:          homeCache,
 		announcementService: announcementService,
 		announcementCtrl:   announcementCtrl,
+		categoryCtrl:       categoryCtrl,
+		categoryService:    categoryService,
+		tagCtrl:            tagCtrl,
+		tagService:         tagService,
 	}
 }

internal/router/frontend.go

@@ -34,12 +34,14 @@ func setupFrontendRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
 				}
 			}
 			announcements, _ := d.announcementService.ListActive()
+			categoryNav, _ := d.categoryService.GetLeaves()
 			c.HTML(http.StatusOK, "home/index.html", common.BuildPageData(c, gin.H{
 				"Title":         "首页",
 				"ExtraCSS":      "/static/css/home.css",
 				"Posts":         posts,
 				"PostCount":     total,
 				"Announcements": announcements,
+				"CategoryNav":   categoryNav,
 			}))
 		})
 
@@ -56,6 +58,9 @@ func setupFrontendRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
 		// 帖子页面
 		pages.GET("/posts", d.postCtrl.ListPage)
 		pages.GET("/posts/:id", d.postCtrl.ShowPage)
+
+		// 标签落地页
+		pages.GET("/tags/:slug", d.tagCtrl.TagPage)
 		pages.GET("/posts/:id/edit", d.authMdw.Required(), func(c *gin.Context) {
 			c.Redirect(http.StatusMovedPermanently, "/studio/write?id="+c.Param("id"))
 		})