permissions.ask: always-prompt list that cannot be bypassed by --dangerously-skip-permissions

Summary

Add a permissions.ask list to settings.json that requires user confirmation even when running in bypass-permissions mode.

Current behavior

settings.json currently supports two lists:

| List | Normal mode | Bypass mode |
|------|-------------|-------------|
| allow | auto-approve | auto-approve |
| (unlisted) | ask | auto-approve |
| deny | block | block |

There is no way to express: "always ask, but don't block."

Desired behavior

Add a permissions.ask list:

| List | Normal mode | Bypass mode |
|------|-------------|-------------|
| allow | auto-approve | auto-approve |
| ask | ask | ask |
| (unlisted) | ask | auto-approve |
| deny | block | block |

Use cases

• Bash(chmod *) / Bash(chown *) — worth confirming, but not worth blocking
• Bash(git push *) — even in automated runs, a human should confirm pushes
• Bash(brew install *) / Bash(npm install *) — dependency changes should be intentional
• Any operation that is low-risk enough to allow but high-impact enough to surface

Why this matters

Bypass mode is useful for autonomous/batch workflows, but it's an all-or-nothing switch today. permissions.ask would let users define a "safety floor" — a set of operations that always surface to the user regardless of how Claude was invoked.