Add `/ask` — Side questions without polluting conversation history

[PureWeen]

Summary

The CLI's /ask command lets users ask a quick side question that doesn't get added to the conversation history. Useful for clarifying something without derailing the main task.

CLI Behavior

• /ask <question> — answer appears but doesn't enter the session history
• The agent's context window is not consumed by side questions

Proposed Implementation

1. "Quick Ask" button or keyboard shortcut (Cmd+Shift+A)
2. Overlay/modal for the side question — visually distinct from main conversation
3. Response appears in a toast or popover — not in the main chat flow
4. No history pollution — the question and answer are ephemeral

Priority: 🟢 LOW