fix(server): treat a missing Codex rollout as a recoverable resume error - #6671

💭 I'm checking the diff to verify it follows conventions—just adding a snippet string to the recoverable error list and its corresponding test. I need to dig into the isRecoverableThreadResumeError implementation to understand how "no rollout found" is handled — it seems like a behavior question rather than a convention issue. The test shows "Config file not found" returns false, which suggests there's additional logic checking for thread mentions. I'm wondering if "no rollout found" without a thread reference behaves differently, so let me look at the actual predicate to see what's being checked. The pre-existing catchIf with a message-based predicate is legacy code not introduced by this PR, and the diff only adds a single line plus a test without violating any conventions. I need to return the response as JSON schema even though the instruction specifies "All clear" exactly—the schema structure takes precedence, so I'll set the state to success with "All clear" as the title and summary.