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/skills/subprocess_script_runner.py

@@ -1,7 +1,6 @@
 # Copyright (c) Microsoft. All rights reserved.
 
 """Sample subprocess-based skill script runner.
-
 Executes file-based skill scripts as local Python subprocesses.
 This is provided for demonstration purposes only.
 """
@@ -18,30 +17,23 @@ from agent_framework import Skill, SkillScript
 
 def subprocess_script_runner(skill: Skill, script: SkillScript, args: dict[str, Any] | None = None) -> str:
     """Run a skill script as a local Python subprocess.
-
     Resolves the script's absolute path from the skill directory, converts
     the ``args`` dict to CLI flags, and returns captured output.
-
     Args:
         skill: The skill that owns the script.
         script: The script to run.
         args: Optional arguments forwarded as CLI flags.
-
     Returns:
         The combined stdout/stderr output, or an error message.
     """
     if not skill.path:
         return f"Error: Skill '{skill.name}' has no directory path."
-
     if not script.path:
         return f"Error: Script '{script.name}' has no file path. Only file-based scripts can be executed locally."
-
     script_path = Path(skill.path) / script.path
     if not script_path.is_file():
         return f"Error: Script file not found: {script_path}"
-
     cmd = [sys.executable, str(script_path)]
-
     # Convert args dict to CLI flags
     if args:
         for key, value in args.items():
@@ -51,7 +43,6 @@ def subprocess_script_runner(skill: Skill, script: SkillScript, args: dict[str,
             elif value is not None:
                 cmd.append(f"--{key}")
                 cmd.append(str(value))
-
     try:
         result = subprocess.run(
             cmd,
@@ -60,15 +51,12 @@ def subprocess_script_runner(skill: Skill, script: SkillScript, args: dict[str,
             timeout=30,
             cwd=str(script_path.parent),
         )
-
         output = result.stdout
         if result.stderr:
             output += f"\nStderr:\n{result.stderr}"
         if result.returncode != 0:
             output += f"\nScript exited with code {result.returncode}"
-
         return output.strip() or "(no output)"
-
     except subprocess.TimeoutExpired:
         return f"Error: Script '{script.name}' timed out after 30 seconds."
     except OSError as e: