Merge https://github.com/google/adk-python/pull/4221
### Link to Issue or Description of Change
N/A
**2. Or, if no issue exists, describe the change:**
Fixing various typos in .py files to improve quality: see commit diffs for details
**Problem:**
See above
**Solution:**
Fixing the typos
### Testing Plan
N/A
**Unit Tests:**
N/A
**Manual End-to-End (E2E) Tests:**
N/A
### Checklist
- [X] I have read the [CONTRIBUTING.md](https://github.com/google/adk-python/blob/main/CONTRIBUTING.md) document.
- [X] I have performed a self-review of my own code.
- [N/A] I have commented my code, particularly in hard-to-understand areas.
- [N/A ] I have added tests that prove my fix is effective or that my feature works.
- [N/A] New and existing unit tests pass locally with my changes.
- [N/A] I have manually tested my changes end-to-end.
- [N/A ] Any dependent changes have been merged and published in downstream modules.
### Additional context
N/A
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/4221 from didier-durand:fix-typos-e 1bcc8e05cdc116451222dd7fd7b0657745f769c1
PiperOrigin-RevId: 859332402
This change introduces a shutdown lifecycle hook for plugins. The `PluginManager` now has an `async def shutdown()` method that will call `await plugin.shutdown()` on any registered plugins that implement the method. This is called from `Runner.close()`, allowing plugins to perform cleanup tasks like flushing logs or closing connections when the runner instance is being closed. This improves the reliability of plugins that perform background operations.
PiperOrigin-RevId: 831037737
Update plugin manager and built-in plugins to prioritize CallbackContext. Keep InvocationContext access for legacy plugins with adapter. Change callback docs/tests to cover the new context.
PiperOrigin-RevId: 818822267
Update plugin manager and built-in plugins to prioritize CallbackContext. Keep InvocationContext access for legacy plugins with adapter. Change callback docs/tests to cover the new context.
PiperOrigin-RevId: 818798087
The `after_agent_callback` in plugin works similarly as the `after_agent_callback` in `base_agent.py`, e.g. it only append new content, but cannot modify the previous content.
PiperOrigin-RevId: 807162139
This CL add new callbacks in plugin system:
- `on_tool_error_callback`
- `on_model_error_callback`
This allow the user to create plugins that can handle errors.
PiperOrigin-RevId: 786469646
Plugin is a collection of callbacks (lifecycle hooks), including callbacks for Agent, Tools, Model and App. It helps developers to add customizations and change behaviors of their agent application easily
This is the first change that introduces only the base interfaces based on the doc.
plugins folder is generated with `create_symlink.sh plugins`
PiperOrigin-RevId: 781745044
Didier DurandandCopybara-Service
George WealeandCopybara-Service
Google Team MemberandCopybara-Service
Wei Sun (Jack)andCopybara-Service
Bastien Jacot-GuillarmodandCopybara-Service
Liang WuandCopybara-Service
Che LiuandCopybara-Service