## Why
On Linux, suspending Codex with `Ctrl+Z` and returning with `fg` can
leave the composer misaligned or inject terminal response bytes such as
focus reports into the prompt. Shell job-control output moves the cursor
while Codex is suspended, and terminal input polling can race with the
responses used to restore the inline viewport.
Fixes#26564.
## What changed
- preserve and restore keyboard reporting without disturbing the parent
terminal stack
- pause terminal event polling while Codex is suspended and flush
buffered input before resuming it
- force crossterm's cached raw-mode state back in sync after the shell
completes its `fg` handoff
- probe the actual post-`fg` cursor position with the tolerant
terminal-response parser, then realign the inline viewport before
redrawing
## How to Test
1. On Linux, start the development TUI with `just c`.
2. Type text into the composer without submitting it.
3. Press `Ctrl+Z`, run any harmless shell command, then run `fg`.
4. Confirm the composer redraws below the shell output, the draft text
is preserved, and no raw escape sequences appear.
5. Repeat the suspend/resume cycle and confirm normal typing still
works.
Targeted tests:
- `cargo test -p codex-tui --lib parses_cursor_position_as_zero_based -j
1`
- `cargo test -p codex-tui --lib tui::event_stream::tests -j 1`
Felipe Coury
76135cbe7e