docs(e2e): point keyless-gate comment at ci.yml (PR) and ci-master.yml (push)

The e2e comment said the keyless gates run in ci.yml on every push/PR; since the
split, master push is covered by ci-master.yml standby instead.

.github/workflows/e2e.yml

@@ -107,7 +107,8 @@ jobs:
         run: pnpm run build
 
       # Real-API end-to-end tests only. The keyless gates (lint/typecheck/
-      # coverage/snapshot/etc.) already run in ci.yml on every push/PR.
+      # coverage/snapshot/etc.) already run in ci.yml (pull requests) and
+      # ci-master.yml (master push standby).
       # DEEPSEEK_BASE_URL is pinned to the external API; the secret is scoped to
       # this step (and preflight) only — never exposed to checkout/setup/install.
       - name: E2E tests (real DeepSeek API)