fix: skip selector keyboard on windows

[amitksingh1490]

Summary

Fix the Windows selector startup failure by skipping crossterm keyboard progressive enhancement on Windows while preserving normal selector input handling.

Context

Fixes #3285.

The selector currently pushes KeyboardEnhancementFlags::DISAMBIGUATE_ESCAPE_CODES during terminal setup. On Windows, crossterm can route that command through the legacy Windows API path for stderr, where keyboard progressive enhancement is unsupported and fails before the selector can render.

Changes

• Gate keyboard progressive enhancement imports and setup to non-Windows platforms.
• Track whether keyboard enhancement was enabled before attempting to pop it during teardown.
• Preserve raw mode, mouse capture, cursor hide/show, and the existing selector event loop behavior.

Key Implementation Details

Windows now returns false from the keyboard enhancement setup helper, so teardown skips PopKeyboardEnhancementFlags. Non-Windows platforms continue to use PushKeyboardEnhancementFlags(KeyboardEnhancementFlags::DISAMBIGUATE_ESCAPE_CODES) as before.

Use Cases

• Windows users can open nucleo-backed list selectors without hitting crossterm's unsupported progressive keyboard enhancement error.
• Basic selector interactions continue to work: typing to filter, arrow navigation, enter/escape, tab multi-select, page up/down, and mouse wheel scrolling.

Testing

cargo check -p forge_select

Links

• Related issues: [Bug]: ERROR: Keyboard progressive enhancement not implemented for the legacy Windows API. #3285