postToolUse hooks not dispatched by runtime

## Summary

postToolUse hooks registered via SDK connections are never invoked by the runtime since version 1.0.13. preToolUse hooks work correctly.

## Affected tests (skipped)

- Node.js: hooks.test.ts - 2 tests
- C#: HooksTests.cs - 2 tests
- Python: test_hooks.py - 2 tests
- Go: hooks_test.go - 2 tests

## Action

Re-enable the skipped tests once the runtime fix ships.