Python: [BREAKING] Python: Provider-leading client design & OpenAI package extraction (#4818)

* Python: Provider-leading client design & OpenAI package extraction

Major refactoring of the Python Agent Framework client architecture:

- Extract OpenAI clients into new `agent-framework-openai` package
- Core package no longer depends on openai, azure-identity, azure-ai-projects
- Rename clients for discoverability: OpenAIResponsesClient → OpenAIChatClient,
  OpenAIChatClient → OpenAIChatCompletionClient
- Unify `model_id`/`deployment_name`/`model_deployment_name` → `model` param
- New FoundryChatClient for Azure AI Foundry Responses API
- New FoundryAgent/FoundryAgentClient for connecting to pre-configured Foundry agents
- Remove OpenAIBase/OpenAIConfigMixin from non-deprecated client MRO
- Deprecate AzureOpenAI* clients, AzureAIClient, OpenAIAssistantsClient
- Reorganize samples: azure_openai+azure_ai+azure_ai_agent → azure/
- ADR-0020: Provider-Leading Client Design

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

* fix: missing Agent imports in samples, .model_id → .model in foundry_local sample

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

* fix: CI failures — mypy errors, coverage targets, sample imports

- azure-ai mypy: add type ignores for TypedDict total=, model arg, forward ref
- Coverage: replace core.azure/openai targets with openai package target
- project_provider: add type annotation for opts dict

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

* fix: populate openai .pyi stub, fix broken README links, coverage targets

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

* fixes

* updated observabilitty

* reset azure init.pyi

* fix errors

* updated adr number

* fix foundry local

* fixed not renamed docstrings and comments, and added deprecated markers to old classes

* fix tests and pyprojects

* fix test vars

* updated function tests

* update durable

* updated test setup for functions

* Fix Foundry auth in workflow samples

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

* Stabilize Python integration workflows

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

* Update hosting samples for Foundry

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

* Trigger full CI rerun

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

* Trigger CI rerun again

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

* trigger rerun

* trigger rerun

* fix for litellm

* undo durabletask changes

* Move Foundry APIs into foundry namespace

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

* Fix Foundry pyproject formatting

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

* Split provider samples by Foundry surface

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

* Restore hosting sample requirements

Also fix the Foundry Local sample link after the provider sample move.

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

* updated tests

* udpated foundry integration tests

* removed dist from azurefunctions tests

* Use separate Foundry clients for concurrent agents

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

* fix client setup in azfunc and durable

* disabled two tests

* updated setup for some function and durable tests

* improved azure openai setup with new clients

* ignore deprecated

* fixes

* skip 11

* remove openai assistants int tests

---------

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

python/samples/02-agents/auto_retry.py

@@ -15,8 +15,8 @@ import logging
 from collections.abc import Awaitable, Callable
 from typing import Any, TypeVar, cast
 
-from agent_framework import ChatContext, ChatMiddleware, SupportsChatGetResponse, chat_middleware
-from agent_framework.azure import AzureOpenAIChatClient
+from agent_framework import Agent, ChatContext, ChatMiddleware, SupportsChatGetResponse, chat_middleware
+from agent_framework.foundry import FoundryChatClient
 from azure.identity import AzureCliCredential
 from dotenv import load_dotenv
 from openai import RateLimitError
@@ -104,7 +104,7 @@ def with_rate_limit_retry(*, retry_attempts: int = RETRY_ATTEMPTS) -> Callable[[
 
 
 @with_rate_limit_retry()
-class RetryingAzureOpenAIChatClient(AzureOpenAIChatClient):
+class RetryingFoundryChatClient(FoundryChatClient):
     """Azure OpenAI Chat client with class-decorator-based retry behavior."""
 
 
@@ -186,7 +186,8 @@ async def class_decorator_example() -> None:
 
     # For authentication, run `az login` command in terminal or replace
     # AzureCliCredential with your preferred authentication option.
-    agent = RetryingAzureOpenAIChatClient(credential=AzureCliCredential()).as_agent(
+    agent = Agent(
+        client=RetryingFoundryChatClient(credential=AzureCliCredential()),
         instructions="You are a helpful assistant.",
     )
 
@@ -204,7 +205,8 @@ async def class_based_middleware_example() -> None:
 
     # For authentication, run `az login` command in terminal or replace
     # AzureCliCredential with your preferred authentication option.
-    agent = AzureOpenAIChatClient(credential=AzureCliCredential()).as_agent(
+    agent = Agent(
+        client=FoundryChatClient(credential=AzureCliCredential()),
         instructions="You are a helpful assistant.",
         middleware=[RateLimitRetryMiddleware(max_attempts=3)],
     )
@@ -223,7 +225,8 @@ async def function_based_middleware_example() -> None:
 
     # For authentication, run `az login` command in terminal or replace
     # AzureCliCredential with your preferred authentication option.
-    agent = AzureOpenAIChatClient(credential=AzureCliCredential()).as_agent(
+    agent = Agent(
+        client=FoundryChatClient(credential=AzureCliCredential()),
         instructions="You are a helpful assistant.",
         middleware=[rate_limit_retry_middleware],
     )
@@ -239,7 +242,7 @@ async def main() -> None:
     print("=== Auto-Retry Rate Limiting Sample ===")
     print(
         "Demonstrates two approaches for automatic retry on rate limit (429) errors.\n"
-        "Set AZURE_OPENAI_ENDPOINT and AZURE_OPENAI_CHAT_DEPLOYMENT_NAME (and optionally\n"
+        "Set AZURE_OPENAI_ENDPOINT and FOUNDRY_MODEL (and optionally\n"
         "AZURE_OPENAI_API_KEY) before running, or populate a .env file."
     )