Merge https://github.com/google/adk-python/pull/3060
## Description
Fixes#3059
This PR fixes two endpoints in `adk web` that fail when using App objects instead of bare agents.
## Changes
- **Eval execution endpoint** (line ~969): Extract root_agent from App objects before passing to LocalEvalService
- **Graph visualization endpoint** (line ~1308): Extract root_agent from App objects before graph operations
Both endpoints now properly handle both BaseAgent and App objects by checking the type and extracting `.root_agent` when needed.
## Testing Plan
### Manual E2E Testing with ADK Web
Tested with an App object that includes context caching:
```python
from google.adk.apps import App
from google.adk.agents import LlmAgent
root_agent = LlmAgent(name="MyAgent", model="gemini-1.5-pro-002")
app = App(
name="my_agent",
root_agent=root_agent,
context_cache_config=ContextCacheConfig(...)
)
```
**Before fix:**
- Graph visualization failed (tried to call agent methods on App object)
- Eval execution failed (LocalEvalService received App instead of agent)
**After fix:**
- Graph visualization works correctly
- Eval execution works correctly
- Both endpoints properly extract root_agent from App objects
## Checklist
- [x] Code follows project style (autoformat.sh passed)
- [x] Changes are focused and minimal
- [x] Issue #3059 created and referenced
- [x] Manual E2E testing completed
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/3060 from ejfn:ejfn/bugfix-app-object-endpoints 01c30191bfd9487a8c8463ccf24b297cb9a4ce37
PiperOrigin-RevId: 821746910
Add a header_provider param which is a callable[ReadonlyContext, Dict[str, Any]] for users to build headers in MCPToolset
fix: https://github.com/google/adk-python/issues/3156
PiperOrigin-RevId: 820412372
This change introduces type aliases for request and event conversion functions:
- `A2ARequestToADKRunArgsConverter`: For converting A2A `RequestContext` to an `ADKRunArgs` Pydantic model.
- `AdkEventToA2AEventsConverter`: For converting ADK `Event` to a list of A2A `A2AEvent` objects.
The `convert_a2a_request_to_adk_run_args` function now returns a structured `ADKRunArgs` model instead of a generic dictionary, improving type safety.
These converter types can now be provided via the `A2aAgentExecutorConfig` to customize the conversion logic used by the `A2aAgentExecutor`. The executor defaults to the existing `convert_a2a_request_to_adk_run_args` and `convert_event_to_a2a_events` functions if no custom converters are specified.
This allows users to inject their own logic for handling request and event conversions, for example, to add custom metadata or transform data types, without modifying the core executor.
PiperOrigin-RevId: 819934960
