* fix(codex): exclude codex-app-server synthetic apiKey from secrets audit
The Codex extension uses the literal string "codex-app-server" as a
hardcoded placeholder apiKey in provider.ts, since the real
authentication is managed by the app-server transport itself.
The secrets audit currently reports this as a real plaintext leak
(PLAINTEXT_FOUND), producing a false positive for any user who has
configured the Codex harness.
Declare it as a plugin-owned non-secret marker in the Codex plugin
manifest, so it flows through the standard
`listKnownNonSecretApiKeyMarkers()` path alongside `ollama-local`,
`lmstudio-local`, `gcp-vertex-credentials`, and `minimax-oauth`.
Also extends the existing `model auth markers` unit tests to lock
in the behavior.
Fixes#69511
* ci: retrigger checks (no-op)