[codex] ROY-22: we should record input tokens and out tokens each time.

[0xroylee]

Linear issue: ROY-22

This PR was created by the PIV Loop workflow.

Includes:

• plan + implement session output
• separate review/testing session

[0xroylee]

PIV loop review for ROY-22

Result: PASS

I reviewed commit 2217a19 for ROY-22, focusing on the new Codex token-usage extraction and run-state recording flow, and I found no functional regressions in the touched paths (src/codex.ts, src/workflow.ts, src/types.ts) or gaps in essential test coverage for the introduced behavior. I executed all required quality gates successfully: bun run check, bun run typecheck, and bun test (42 passed, 0 failed), and based on code inspection plus passing validation, the change is safe to merge.

No bugs found.