[FEATURE] hooks: PermissionRequest and PreToolUse: Support `updatedInput` without requiring `permissionDecision`

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

PermissionRequest hook doesn't allow specifying updatedInput without permissionDecision in the output. It can't serve the needs where the user only wants to modify the input (like sanitization or normalization) without touching how Claude Code handles the permission. The current design forces the hook to decide up-front.

Proposed Solution

Allow updatedInput without permissionDecision

Alternative Solutions

None.

Priority

High - Significant impact on productivity

Feature Category

Configuration and settings

Use Case Example

_No response_

Additional Context

https://github.com/anthropics/claude-agent-sdk-python/issues/381