* Evaluation dataset schema is finalized with strong-type pydantic models.
(previously saved eval file needs re-generation, for both adk eval cli and
the eval tab in adk web UI).
*`BuiltInCodeExecutor` (in code_executors package) replaces
`BuiltInCodeExecutionTool` (previously in tools package).
* All methods in services are now async, including session service, artifact
service and memory service.
*`list_events` and `close_session` methods are removed from session service.
* agent.py file structure with MCP tools are now easier and simpler ([now](https://github.com/google/adk-python/blob/3b5232c14f48e1d5b170f3698d91639b079722c8/contributing/samples/mcp_stdio_server_agent/agent.py#L33) vs [before](https://github.com/google/adk-python/blob/a4adb739c0d86b9ae4587547d2653d568f6567f2/contributing/samples/mcp_agent/agent.py#L41)).
Old format is not working anymore.
*`Memory` schema and `MemoryService` is redesigned.
* Mark various class attributes as private in the classes in the `tools` package.
* Disabled session state injection if instruction provider is used.
(so that you can have `{var_name}` in the instruction, which is required for code snippets)
* Toolbox integration is revamped: tools/toolbox_tool.py → tools/toolbox_toolset.py.
* Removes the experimental `remote_agent.py`. We'll redesign it and bring it back.
### Features
* Dev UI:
* A brand new trace view for overall agent invocation.
* A revamped evaluation tab and comparison view for checking eval results.
* Introduced `BaseToolset` to allow dynamically add/remove tools for agents.
* Revamped MCPToolset with the new BaseToolset interface.
* Revamped GoogleApiTool, GoogleApiToolset and ApplicationIntegrationToolset with the new BaseToolset interface.
* Resigned agent.py file structure when needing MCPToolset.
* Set the max size of strings in database columns. MySQL mandates that all VARCHAR-type fields must specify their lengths.
* Extract content encode/decode logic to a shared util, resolve issues with JSON serialization, and update key length for DB table to avoid key too long issue in mysql.
* Enhance `FunctionTool` to verify if the model is providing all the mandatory arguments.
### Features
* Update ADK setup guide to improve onboarding experience.
* feat: add ordering to recent events in database session service.
* feat(llm_flows): support async before/after tool callbacks.
* feat: Added --replay and --resume options to adk run cli. Check adk run --help for more details.
* Created a new Integration Connector Tool (underlying of the ApplicationIntegrationToolSet) so that we do not force LLM to provide default value.
### Bug Fixes
* Don't send content with empty text to LLM.
* Fix google search reading undefined for `renderedContent`.
### Miscellaneous Chores
* Docstring improvements, typo fixings, github action to enfore code styles on formatting and imports, etc.