[codex] surface rollout budget exhaustion (#29715)

## Summary
- surface shared rollout-budget exhaustion as
`CodexErr::RolloutBudgetExceeded` instead of a generic interrupted turn
- map it through the existing `CodexErrorInfo` and app-server v2
`codexErrorInfo` path
- keep local compaction from retrying after the shared rollout budget is
exhausted

This gives app-server clients a stable `rolloutBudgetExceeded` error
they can classify without guessing from `status="interrupted"`.

## Tests
- `just test -p codex-core rollout_budget`

codex-rs/app-server/README.md

@@ -1423,6 +1423,7 @@ There are additional item-specific events:
 `codexErrorInfo` maps to the `CodexErrorInfo` enum. Common values:
 
 - `ContextWindowExceeded`
+- `RolloutBudgetExceeded`
 - `UsageLimitExceeded`
 - `HttpConnectionFailed { httpStatusCode? }`: upstream HTTP failures including 4xx/5xx
 - `ResponseStreamConnectionFailed { httpStatusCode? }`: failure to connect to the response SSE stream