feat: add Yuheng ticket bind, trial SMS off, shared bindings

Ship ticket-exchange and bind/policy for Z13, keep trial binds SMS-free, allow shared company bindings, and align SyncPage plus sync docs.

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

gateway/gateway.go

@@ -39,6 +39,12 @@ func main() {
 			"/api/v1/auth/register",
 			"/api/v1/auth/token",
 			"/api/v1/auth/agent/register",
+			"/api/v1/auth/bind-code/redeem",
+			"/api/v1/auth/bind/phone-lookup",
+			"/api/v1/auth/bind/phone-confirm",
+			"/api/v1/auth/bind/policy",
+			"/api/v1/auth/yuheng/ticket-exchange",
+			"/api/v1/auth/sms/send",
 			"/api/v1/meta/",
 			"/api/v1/public/",
 			"/ai/",