Update SKILL.md with alert checking and response handling

[yossiovadia]

Task

Update the claude-code-wingman skill to handle approval alerts and user responses.

Implementation

• Add periodic check for /tmp/claude-monitor-*.alert files
• Parse alert JSON and present to user via WhatsApp
• Handle user responses (approve/always/deny/wait)
• Support both numeric (1/2/3) and natural language responses
• Forward response to tmux session
• Clean up alert file after handling
• Send reminders for unhandled alerts

Acceptance Criteria

• Alerts are detected and presented to user
• All response types are handled correctly
• Responses are forwarded to correct session
• Reminders work as expected
• Alert files are cleaned up properly

Related

Part of #8, depends on #9