feat: account ensure-web (pick-or-create for first-run UX)

scripts/service/account_service.py

@@ -15,6 +15,7 @@ PyArmor trial per-file line limits. This module re-exports the public API.
 """
 from service._svc_common import PlatformCallerMeta
 from service.account_add_commands import cmd_account_add_secret, cmd_account_add_web
+from service.account_ensure_commands import cmd_account_ensure_web
 from service.account_mark_commands import (
     cmd_account_mark_error,
     cmd_account_mark_session,
@@ -43,6 +44,7 @@ __all__ = [
     "PlatformCallerMeta",
     "cmd_account_add_secret",
     "cmd_account_add_web",
+    "cmd_account_ensure_web",
     "cmd_account_get",
     "cmd_account_get_credential",
     "cmd_account_list",