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

The new session_files_for_cwd function in src/sdk/src/session_history/scan.rs looks sound. It resolves the target cwd first and returns empty on failure (preventing the None-equals-None misattribution it documents), sorts collected files newest-first, and filters to those whose recorded session cwd resolves to the same canonical path. The ? operator inside filter_map correctly skips files with no summary or no recorded cwd, matching the documented contract that a transcript without a cwd is not a candidate. The as_deref() / as_str() comparison is type-consistent assuming safe_resolve returns Option<String>, which the surrounding here.as_str() usage confirms. No bugs introduced by this change. The three prior findings were checked against the visible diff but none of them appear to concern code shown in this file's change, so they cannot be confirmed or refuted from here. (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still open) The code index is behind this pull request (indexed at 682126fd3751), so retrieved context may be out of date.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 — not visible in this file's diff; cannot verify from here.
• Empty OSC title behavior change is unmentioned — not visible in this file's diff; cannot verify from here.
• Use the same winning record for duplicate Codex index ids in single and batch — not visible in this file's diff; cannot verify from here.