feat: 可选社区上报与官方精选展柜

默认关闭，仪表盘一键开关；枢纽由运维配置收报，人工精选后展示于 /showcase。

Co-authored-by: Cursor <cursoragent@cursor.com>

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/gin-gonic/gin v1.10.0
 	github.com/glebarez/sqlite v1.11.0
 	github.com/golang-jwt/jwt/v5 v5.2.1
+	github.com/google/uuid v1.6.0
 	github.com/kardianos/service v1.2.2
 	github.com/microcosm-cc/bluemonday v1.0.27
 	github.com/minio/minio-go/v7 v7.0.98
@@ -31,7 +32,6 @@ require (
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/go-playground/validator/v10 v10.20.0 // indirect
 	github.com/goccy/go-json v0.10.2 // indirect
-	github.com/google/uuid v1.6.0 // indirect
 	github.com/gorilla/css v1.0.1 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect