[BREAKING] Python: clean up kwargs across agents, chat clients, tools, and sessions (#4581)

* Python: clean up kwargs across agents, chat clients, tools, and sessions (#3642)

Audit and refactor public **kwargs usage across core agents, chat clients,
tools, sessions, and provider packages per the migration strategy codified
in CODING_STANDARD.md.

Key changes:
- Add explicit runtime buckets: function_invocation_kwargs and client_kwargs
  on RawAgent.run() and chat client get_response() layers.
- Refactor FunctionTool to prefer explicit ctx: FunctionInvocationContext
  injection; legacy **kwargs tools still work via _forward_runtime_kwargs.
- Refactor Agent.as_tool() to use direct JSON schema, always-streaming
  wrapper, approval_mode parameter, and UserInputRequiredException
  propagation (integrates PR #4568 behavior).
- Remove implicit session bleeding into FunctionInvocationContext; tools
  that need a session must receive it via function_invocation_kwargs.
- Lower chat-client layers after FunctionInvocationLayer accept only
  compatibility **kwargs (client_kwargs flattened, function_invocation_kwargs
  ignored).
- Add layered docstring composition from Raw... implementations via
  _docstrings.py helper.
- Clean up provider constructors to use explicit additional_properties.
- Deprecation warnings on legacy direct kwargs paths.
- Update samples, tests, and typing across all 23 packages.

Resolves #3642

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* clarified docstring

* feedback fixes

* Add unit tests for _docstrings.py build/apply helpers

Tests cover: no docstring source, no extra kwargs, appending to existing
Keyword Args section, inserting after Args, inserting in plain docstrings,
multiline descriptions, ordering, and apply_layered_docstring.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Add test for propagate_session TypeError on non-AgentSession values

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Add tests for multi-content and empty UserInputRequiredException propagation

Cover the branching logic in _try_execute_function_calls for:
- Multiple user_input_request items in a single exception (extra_user_input_contents path)
- Empty contents list (fallback function_result path)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Add tests for DurableAIAgent.get_session forwarding service_session_id

Verifies get_session correctly forwards service_session_id and session_id
to the executor's get_new_session, replacing the removed kwargs test.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Simplify ag-ui test stub to read session from client_kwargs only

Remove dual-mode detection (client_kwargs vs raw kwargs fallback) from
the test mock. Session is now read exclusively from client_kwargs,
matching the settled public calling convention.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* updated create and get sessions in durable

* fixed docstrings

* fix test

* updated session handling

* updated from main

* updated tests

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

python/packages/claude/agent_framework_claude/_agent.py

@@ -590,6 +590,7 @@ class RawClaudeAgent(BaseAgent, Generic[OptionsT]):
         *,
         stream: Literal[False] = ...,
         session: AgentSession | None = None,
+        options: OptionsT | None = None,
         **kwargs: Any,
     ) -> Awaitable[AgentResponse[Any]]: ...
 
@@ -600,6 +601,7 @@ class RawClaudeAgent(BaseAgent, Generic[OptionsT]):
         *,
         stream: Literal[True],
         session: AgentSession | None = None,
+        options: OptionsT | None = None,
         **kwargs: Any,
     ) -> ResponseStream[AgentResponseUpdate, AgentResponse[Any]]: ...
 
@@ -609,7 +611,8 @@ class RawClaudeAgent(BaseAgent, Generic[OptionsT]):
         *,
         stream: bool = False,
         session: AgentSession | None = None,
-        **kwargs: Any,
+        options: OptionsT | None = None,
+        **kwargs: Any,  # type: ignore
     ) -> Awaitable[AgentResponse[Any]] | ResponseStream[AgentResponseUpdate, AgentResponse[Any]]:
         """Run the agent with the given messages.
 
@@ -621,16 +624,16 @@ class RawClaudeAgent(BaseAgent, Generic[OptionsT]):
                 returns an awaitable AgentResponse.
             session: The conversation session. If session has service_session_id set,
                 the agent will resume that session.
-            kwargs: Additional keyword arguments including 'options' for runtime options
-                (model, permission_mode can be changed per-request).
+            options: Runtime options. Model and permission_mode can be changed per request.
+            kwargs: Additional keyword arguments for compatibility with the shared agent
+                interface (e.g. compaction_strategy, tokenizer). Not used by ClaudeAgent.
 
         Returns:
             When stream=True: An ResponseStream for streaming updates.
             When stream=False: An Awaitable[AgentResponse] with the complete response.
         """
-        options = kwargs.pop("options", None)
         response = ResponseStream(
-            self._get_stream(messages, session=session, options=options, **kwargs),
+            self._get_stream(messages, session=session, options=options),
             finalizer=self._finalize_response,
         )
 
@@ -643,8 +646,7 @@ class RawClaudeAgent(BaseAgent, Generic[OptionsT]):
         messages: AgentRunInputs | None = None,
         *,
         session: AgentSession | None = None,
-        options: OptionsT | MutableMapping[str, Any] | None = None,
-        **kwargs: Any,
+        options: OptionsT | None = None,
     ) -> AsyncIterable[AgentResponseUpdate]:
         """Internal streaming implementation."""
         session = session or self.create_session()