[Bug]: Windows compatibility crashes ('termios' ModuleNotFoundError & KernelClient AttributeError)

[Yash-Kavaiya]

Description

Running google-colab-cli commands on Windows 11 / Windows PowerShell causes runtime crashes due to un-guarded Unix-specific standard library modules (termios, tty, signal.SIGWINCH, and /dev/tty) and a deprecated KernelClient attribute reference.

Steps to Reproduce

1. Install google-colab-cli on Windows.
2. Run colab new -s my-session.

Stack Trace / Error Logs

Traceback (most recent call last):
  File "C:\Users\yashk\AppData\Roaming\uv\tools\google-colab-cli\Lib\site-packages\colab_cli\cli.py", line 26, in <module>
    from colab_cli.commands import session, execution, files, automation, run, utility
  File "C:\Users\yashk\AppData\Roaming\uv\tools\google-colab-cli\Lib\site-packages\colab_cli\commands\execution.py", line 29, in <module>
    from colab_cli.console import connect_console
  File "C:\Users\yashk\AppData\Roaming\uv\tools\google-colab-cli\Lib\site-packages\colab_cli\console.py", line 20, in <module>
    import termios
ModuleNotFoundError: No module named 'termios'

Additionally, during execution:

AttributeError: module 'jupyter_kernel_client' has no attribute 'KernelClient'

Proposed Solution

1. colab_cli/console.py: Wrap termios and tty imports in try/except ImportError and guard termios, tty, fileno(), and signal.SIGWINCH usage.
2. colab_cli/commands/automation.py: Add a try/except (OSError, FileNotFoundError) fallback for open("/dev/tty") to sys.stdin.readline().
3. colab_cli/runtime.py: Update jupyter_kernel_client.KernelClient reference to jupyter_kernel_client.JupyterKernelClient.

PR #99 has been opened to resolve these issues.