bug: Shell escape (!) in --tui mode does not yield terminal stdin to interactive subprocesses

[ElBlackwood]

Checks

• I have searched github.com/aws/amazon-q-developer-cli/issues and there are no duplicates of my
  issue
• I have run q doctor in the affected terminal session
• I have run q restart and replicated the issue again

Operating system

Ubuntu 24.04 LTS on WSL2 (kernel 6.6.87.2-microsoft-standard-WSL2)

Expected behaviour

When running an interactive command via the ! shell escape in --tui mode (e.g. !my-script where the script uses read -r to wait for user input), the CLI
should temporarily:

1. Save the TUI terminal state
2. Restore the terminal to cooked mode
3. Yield stdin to the child process
4. Re-enter TUI/raw mode when the subprocess exits
   This is the standard pattern used by other TUI applications that support shell escapes (vim :!cmd, less !cmd, htop, etc.).
   The non-TUI kiro-cli chat mode handles ! commands correctly — this is specific to --tui.

Actual behaviour

In --tui mode, the TUI retains raw terminal control and does not yield stdin to the subprocess. This causes two failure modes depending on how the script reads
input:

1. read -r (from stdin): Gets immediate EOF — the script doesn't wait for input and exits instantly
2. read -r </dev/tty (from terminal device): Hangs indefinitely — /dev/tty is accessible but the TUI's raw mode input loop is consuming all keypresses.
   Enter and Ctrl+C never reach the subprocess. The only recovery is force-killing kiro-cli from another terminal.

Steps to reproduce

1. Create a minimal interactive script:

#!/usr/bin/env bash
echo "Press Enter to continue..." >&2
read -r
echo "Done!" >&2

Save as ~/bin/test-interactive, chmod +x.
2. Start kiro-cli in TUI mode:

kiro-cli chat --tui

3. Run the script via shell escape:

> !test-interactive

Result: Script either exits instantly (stdin EOF) or hangs forever (/dev/tty blocked by TUI). Terminal becomes unresponsive to Ctrl+C.
4. Compare with non-TUI mode:

kiro-cli chat
> !test-interactive

Result: Works correctly — waits for Enter, then prints "Done!".

Real-world impact

A voice recording script that uses read -r to wait for Enter (to stop recording) cannot be used via ! in TUI mode. The recording either captures nothing
(immediate exit) or requires force-killing the process.

Additional context

• PR feat(tools): execute_bash uses PTY for shell integrations #1340 (feat(tools): execute_bash uses PTY for shell integrations) addressed a related issue for the execute_bash tool but was closed without merging.
• The fix pattern is well-established: save terminal state → tcsetattr to restore cooked mode → fork/exec with inherited stdin/stdout/stderr → waitpid →
  restore TUI raw mode. This is how ncurses endwin()/refresh() and crossterm disable_raw_mode()/enable_raw_mode() handle it.

Environment

[q-details]
version = "1.28.1"
hash = "fc92565d6f51c1708e92500b2b2bcc4a424f5705"
date = "2026-03-21T05:18:11.590914Z"
variant = "minimal"
[system-info]
chip = "Intel(R) Core(TM) Ultra 7 265H"
total-cores = 16
memory = "15.35 GB"
[system-info.os.linux]
kernel_version = "6.6.87.2-microsoft-standard-WSL2"
id = "ubuntu"
name = "Ubuntu"
pretty_name = "Ubuntu 24.04 LTS"
version_id = "24.04"
[environment]
os = "Linux"
shell-path = "/bin/bash"
in-wsl = true