feat(hooks): support 'decision: ask' to force user confirmation

[SandyTao520]

Description

Support a new hook decision ask that allows a hook to force a user confirmation prompt, even if a tool is currently allowlisted or the user is running in 'YOLO' mode. This is useful for sensitive operations that require manual oversight regardless of general security policies.

Proposed Behavior

When a BeforeTool hook returns decision: 'ask':

1. The CoreToolScheduler should interrupt its normal auto-approval logic.
2. The user should be presented with the standard interactive confirmation prompt for that tool.
3. The hook's systemMessage (if provided) should be displayed to explain why the confirmation is being forced.

Implementation Details

1. Move the BeforeTool hook trigger point from executeToolWithHooks into CoreToolScheduler._processNextInQueue.
2. Fire the hook before the isAutoApproved check.
3. Update isAutoApproved (or the logic surrounding it) to respect the hook's decision, prioritizing ask as a requirement for manual confirmation.

[gundermanc]

Blocked on core tools scheduler refactor.