## What changed
- Use Ratatui-compatible terminal widths throughout TUI layout, preserving
full-width counters for long lines.
- Wrap and truncate on grapheme boundaries so halfwidth kana sound marks and
emoji sequences stay intact.
- Apply the corrected sizing to text input, selection popups, status and
history cells, Markdown, hyperlinks, and scrollable cloud diffs.
## Testing
- Add focused unit and snapshot coverage for wrapping, truncation, cursor and
mask alignment, popup columns, status output, session headers, Markdown
tables, process output, and scrollable diffs.
GitOrigin-RevId: 294ec0bcff743c6bb16d55ec26308524ce741879
## Summary
- reduce public module visibility across Rust crates, preferring private
or crate-private modules with explicit crate-root public exports
- update external call sites and tests to use the intended public crate
APIs instead of reaching through module trees
- add the module visibility guideline to AGENTS.md
## Validation
- `cargo check --workspace --all-targets --message-format=short` passed
before the final fix/format pass
- `just fix` completed successfully
- `just fmt` completed successfully
- `git diff --check` passed
