[BUG] Windows Alt+V shortcut not documented - users receive inaccurate CTRL+V paste tooltip instructions

Environment

• Platform (select one):
• [ ] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [x] Other: Claude Code
• Claude CLI version: 1.0.100
• Operating System: Windows 11 (MINGW64_NT-10.0-19045)
• Terminal: Git Bash

## Bug Description
Windows users are not informed about the correct keyboard shortcuts for Claude Code. The application displays or implies CTRL+V for paste operations, but the actual working shortcut on Windows is ALT+V. This creates confusion and makes functionality appear broken.

## Steps to Reproduce

1. Install Claude Code on Windows + Git for Windows
2. Launch Claude Code in Git Bash terminal
3. Take a screenshot with Windows+Shift+S
4. Try to paste content using CTRL+V (standard Windows paste shortcut)
5. Observe that CTRL+V does not work
6. Check official documentation at https://docs.anthropic.com/en/docs/claude-code/interactive-mode
7. Note that ALT+V is not mentioned anywhere in official documentation

## Expected Behavior

• Windows users should see ALT+V clearly documented in official documentation
• Tooltips/help text should show platform-appropriate shortcuts
• Documentation should explicitly state platform differences
• Users should not have to discover ALT+V through trial and error

## Actual Behavior

• Official documentation does not mention ALT+V anywhere
• Users attempt CTRL+V and think paste functionality is broken
• No platform-specific shortcut reference exists in official docs
• Users must discover ALT+V through GitHub issues or community support

## Additional Context

Related Issues:

• #6756: [Bug] Keyboard Navigation and Image Paste Functionality Broken

Evidence of Documentation Gap:

• Searched all official Anthropic documentation (docs.anthropic.com)
• ALT+V is mentioned in GitHub issue #6756, not in official docs
• Interactive mode keyboard shortcuts page has no Windows-specific instructions
• CLI reference has no mention of platform-specific shortcuts

Impact:

• Poor user experience for Windows users
• Increased support burden from users thinking features are broken
• Platform inequality between Windows and macOS/Linux users
• Users waste time troubleshooting non-existent problems

Suggested Solutions:

1. Update Official Documentation:

• Add Platform-specific shortcuts to keyboard shortcuts reference
• Include platform differences in CLI reference
• Update help system to show ALT+V for Windows users

1. Dynamic Platform Detection:

• Show platform-appropriate shortcuts in tooltips
• Runtime detection of OS for help text
• Consider CTRL+V alias for ALT+V on Windows for consistency

1. Comprehensive Platform Guide:

• Create dedicated Windows setup/usage section
• Include troubleshooting for platform-specific issues
• Document all known Windows limitations/workarounds

Current Workaround:
Windows users can use ALT+V for paste operations, but this is completely undocumented and must be discovered through community sources.