feat: surface installed hook actions during apm install

[harshitlarl]

Summary

• show concise per-event hook action summaries during apm install
• include the full rewritten hook JSON in verbose mode so developers can review deployed hook content
• add focused tests covering the new install-time transparency output

Testing

• . .venv/bin/activate && pytest tests/unit/test_install_hook_transparency.py tests/unit/integration/test_hook_integrator.py -n0

Closes #316

[harshitlarl]

@microsoft-github-policy-service agree

[harshitlarl]

Closing this in favor of #409, which uses a neutral branch name and contains the same changes.