Plan mode: 'Clear context and implement' as default is destructive and irreversible

Problem

When exiting plan mode to implement, the default option is now "Clear context and implement" instead of "Implement". This is a destructive action as the default choice — pressing Enter too quickly selects it, wiping the entire conversation context irreversibly.

To make matters worse, clearing context also wipes the terminal scrollback history, so the user can't even scroll up to see what was discussed. The plan transcript and all prior conversation context are gone permanently.

Impact

• Users lose carefully developed plans, design discussions, and implementation context
• There's no confirmation step or undo
• The terminal history wipe means there's no way to recover — not even by reading the screen
• Violates the principle of least surprise: the most destructive option should never be the default

Suggested Fix

• Make "Implement" (preserve context) the default option
• Or at minimum, add a confirmation prompt before clearing context: "This will clear your conversation history. Continue?"
• Do not wipe terminal scrollback — that's the user's shell history, not Claude Code's to clear

Environment

• Claude Code CLI
• Observed on Linux (Pop!_OS / Ubuntu-based)