Add filtered resume picker snapshots and render filter hint

[joshka-oai]

Motivation

• Ensure the resume picker shows a one-line filter hint when not run with --all so users see that results are filtered and how to show all sessions.
• Normalize and surface the current working directory used in the hint so the path display is consistent between tui and tui2.
• Reserve layout space for the extra hint row so previews, pagination, and hint rows do not overlap.
• Add snapshot coverage for the filtered (non---all) rendering to prevent regressions.

Description

• Add a display_cwd: Option<PathBuf> field to PickerState and pass std::env::current_dir() into PickerState::new via the run_resume_picker callers.
• Implement render_filter_hint_line (shared pattern in both tui and tui2) to render the one-line filter/--all hint using display_cwd and existing styling.
• Adjust layout constraints in draw_picker to add a Constraint::Length(1) for the new hint row and subtract the extra row from the list height calculations.
• Add new snapshot tests and snapshot files resume_picker_screen_filtered for both tui and tui2 to exercise the filtered hint rendering.

Testing

• Ran just fmt and it completed successfully.
• Ran just fix -p codex-tui and just fix -p codex-tui2 (Clippy autofixes) and they completed successfully.
• Ran cargo test -p codex-tui and cargo test -p codex-tui2 and all tests passed after updating/adding the new snapshots.
• Committed the new snapshot files for the filtered resume picker screens so CI will exercise them going forward.

---

Codex Task

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: e775b31d37

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[joshka-oai]

[nornagon-openai]

I think the --all hint is worse than having a keyboard shortcut that toggles the filter

[joshka-oai]

I think the --all hint is worse than having a keyboard shortcut that toggles the filter

I agree - this is a small stop gap solution until we change that.
I didn't have a huge amount of time to test / dig into a more detailed behavior fix like that, so figured a messaging change was the simplest thing to help reduce the confusion about this behavior.