Secrets: reject exec SecretRef traversal ids across schema/runtime/gateway (#42370)

* Secrets: harden exec SecretRef validation and reload LKG coverage

* Tests: harden exec fast-exit stdin regression case

* Tests: align lifecycle daemon test formatting with oxfmt 0.36

src/commands/auth-choice.apply-helpers.ts

@@ -8,6 +8,8 @@ import {
 import { encodeJsonPointerToken } from "../secrets/json-pointer.js";
 import { PROVIDER_ENV_VARS } from "../secrets/provider-env-vars.js";
 import {
+  formatExecSecretRefIdValidationMessage,
+  isValidExecSecretRefId,
   isValidFileSecretRefId,
   resolveDefaultSecretProviderAlias,
 } from "../secrets/ref-contract.js";
@@ -238,6 +240,9 @@ export async function promptSecretRefForOnboarding(params: {
         ) {
           return 'singleValue mode expects id "value".';
         }
+        if (providerEntry.source === "exec" && !isValidExecSecretRefId(candidate)) {
+          return formatExecSecretRefIdValidationMessage();
+        }
         return undefined;
       },
     });