refactor: CSP nonce替代unsafe-inline, HSTS始终启用, router/api拆分, 管理后台+用户设置页拆分, DB健康降级, 时区配置, UID统一解析, CI接入

审计修复:
- CSP: unsafe-inline移除, nonce替代; unsafe-eval保留供Vditor使用
- HSTS: 始终启用(不再依赖release模式)
- Controller Exp: common.GetGinExp包装, 不再直接读context
- UID解析: common.ParseUIDParam统一, follow/admin controller改用

重构:
- router/api.go(198行)拆为7个域文件: auth/settings/posts/comments/reactions/social/studio
- 管理后台站点设置: 单页拆为4个子页(brand/security/registration/content)+子菜单
- 前台用户设置页: 1201行拆为6个独立模板+6个独立JS文件

新增:
- DB健康检测中间件(middleware/db_health.go): 5s ping+降级页面
- 时区配置: config.yaml server.timezone→time.Local初始化
- .gitea/workflows/ci.yml: strict模式CI流水线

internal/router/api_reactions.go

@@ -0,0 +1,24 @@
+package router
+
+import (
+	"metazone.cc/mce/internal/config"
+	"metazone.cc/mce/internal/middleware"
+
+	"github.com/gin-gonic/gin"
+)
+
+// setupReactionsAPIRoutes 注册赞/踩相关 API 路由
+func setupReactionsAPIRoutes(r *gin.Engine, cfg *config.Config, d *dependencies) {
+	// 公开：查询反应状态
+	r.GET("/api/posts/:id/reaction", d.reactionCtrl.GetReaction)
+
+	// 需登录：切换赞/踩
+	reactionAPI := r.Group("/api/posts/:id")
+	reactionAPI.Use(d.authMdw.Required())
+	reactionAPI.Use(d.authMdw.BannedWriteGuard())
+	reactionAPI.Use(middleware.CSRF(cfg))
+	{
+		reactionAPI.POST("/like", d.reactionCtrl.ToggleLike)
+		reactionAPI.POST("/dislike", d.reactionCtrl.ToggleDislike)
+	}
+}