feat(ECR-044): RhythmConfig 写面闭环并 Closed

复用 admin.explore.write、POST/PUT+审计、C端 GET /rhythm/configs、
H5 无 active 空态/失败回退；migration 000053。ExploreConfig Loop STOP，禁自动 ECR-045。

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

apps/api/internal/httpserver/router.go

@@ -102,6 +102,7 @@ func NewRouter(pool *pgxpool.Pool, cfg config.Config) *gin.Engine {
 	(&handler.AnalyticsHandler{Svc: analyticsSvc}).Register(authed)
 	(&handler.HomeHandler{Svc: homeSvc}).Register(authed)
 	(&handler.StarConfigPublicHandler{Repo: adminRepo}).Register(authed)
+	(&handler.RhythmConfigPublicHandler{Repo: adminRepo}).Register(authed)
 
 	gated := authed.Group("")
 	gated.Use(middleware.RequireRegistered(pool))