Preserve turn attribution across recovery and compaction (#51402)

## Why

Recovering an interrupted turn replaced its original trigger with `retry` and restored only its root lineage from model context. Turns suspended before that context was written could lose their attribution entirely.

## What changed

- Persist regular-turn attribution in `TurnStartedEvent` and compaction resume metadata, including the trigger, parent and root turn IDs, and initiating agent path.
- Restore matching attribution during recovery, keep unknown triggers absent, and retain the model-context root fallback for older records.
- Reconstruct attribution from surviving turns across rollback and late completion or abort events, and clear inherited attribution when spawning a forked agent.

## Testing

Add coverage for repeated cold recovery, suspension before context persistence, legacy rollouts, fresh attribution on subsequent turns, compaction checkpoints, rollback, and late terminal events.

GitOrigin-RevId: 85b5763e8fbd48a1ea2c07cfda8196e63c2cd33a

codex-rs/core/src/agent/control/spawn.rs

@@ -1201,6 +1201,7 @@ impl LocalAgentControl {
                     compacted.latest_token_usage_record = None;
                     if let Some(resume_metadata) = &mut compacted.resume_metadata {
                         resume_metadata.multi_agent_version = Some(multi_agent_version);
+                        resume_metadata.turn_attribution = None;
                         if !preserve_context_baselines {
                             resume_metadata.previous_turn_settings = None;
                         }