fix(tui): show Codex thread labels - #253

All three prior findings are resolved by the updated PR description, and the newly added session_files_for_cwd function in scan.rs is covered by the body's mention of recovering labels 'by session ID or working directory.' The implementation is clean: it guards against unresolvable cwds, excludes transcripts with no recorded cwd (documented as intentional), and sorts newest-first before filtering to exact-cwd matches. The description accurately matches what the diff does — no unmentioned significant changes, no claims the code does not back up. (3 earlier finding(s) still open) The code index is behind this pull request (indexed at 682126fd3751), so retrieved context may be out of date.

No findings.

Fixed since the last review

• Per-session timer poller for Codex thread names is unmentioned — the PR body now explicitly describes the per-session label poller, its 2-second interval, where it lives (labels.rs), where it is spawned (PTY manager), and its dedicated e2e test.
• Empty OSC title behavior change is unmentioned — the PR body now documents both the change (empty OSC titles no longer clear the thread name) and the rationale, under its own 'Behavior change' heading.
• Use the same winning record for duplicate Codex index ids in single and batch — codex_thread_label routes through codex_index_map, so both paths use the same last-wins collection; a dedicated test (codex_thread_label_and_index_map_agree_on_duplicate_ids) asserts agreement.