Add 'panic mode' - quick undo last N minutes

[dinakars777]

Description

Add a quick "panic mode" that lets users instantly undo all changes from the last N minutes.

Suggested Implementation

• Add --panic <minutes> CLI flag
• Automatically find the reflog entry from N minutes ago
• Show confirmation: "Restore to state from 15 minutes ago?"
• Execute restore without opening full TUI

Example Usage

git-time-machine --panic 15  # Undo last 15 minutes
git-time-machine --panic 60  # Undo last hour

Technical Details

• Add panic field to Cli struct
• Parse reflog timestamps
• Find first entry older than N minutes
• Show simple confirmation prompt
• Execute git reset --hard

Why This is a Good First Issue

• Small, focused feature
• Minimal UI changes
• Good introduction to CLI argument handling
• Clear acceptance criteria

Related to roadmap item: 'Panic mode' - undo last N minutes