Foundry Evals integration for Python

Merged and refactored eval module per Eduard's PR review:

- Merge _eval.py + _local_eval.py into single _evaluation.py
- Convert EvalItem from dataclass to regular class
- Rename to_dict() to to_eval_data()
- Convert _AgentEvalData to TypedDict
- Simplify check system: unified async pattern with isawaitable
- Parallelize checks and evaluators with asyncio.gather
- Add all/any mode to tool_called_check
- Fix bool(passed) truthy bug in _coerce_result
- Remove deprecated function_evaluator/async_function_evaluator aliases
- Remove _MinimalAgent, tighten evaluate_agent signature
- Set self.name in __init__ (LocalEvaluator, FoundryEvals)
- Limit FoundryEvals to AsyncOpenAI only
- Type project_client as AIProjectClient
- Remove NotImplementedError continuous eval code
- Add evaluation samples in 02-agents/ and 03-workflows/
- Update all imports and tests (167 passing)

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

python/samples/03-workflows/evaluation/evaluate_workflow.py

@@ -0,0 +1,60 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+"""Evaluate a multi-agent workflow with per-agent breakdown.
+
+Demonstrates workflow evaluation:
+1. Build a simple two-agent workflow
+2. Run evaluate_workflow() which runs the workflow and evaluates each agent
+3. Inspect per-agent results in sub_results
+
+Usage:
+    uv run python samples/03-workflows/evaluation/evaluate_workflow.py
+"""
+
+import asyncio
+
+from agent_framework import (
+    Agent,
+    AgentExecutor,
+    LocalEvaluator,
+    WorkflowBuilder,
+    evaluate_workflow,
+    evaluator,
+    keyword_check,
+)
+
+
+@evaluator
+def is_nonempty(response: str) -> bool:
+    """Check the agent produced a non-trivial response."""
+    return len(response.strip()) > 5
+
+
+async def main():
+    # Build a simple planner → executor workflow
+    planner = Agent(model="gpt-4o-mini", instructions="You plan trips. Output a bullet-point plan.")
+    executor_agent = Agent(model="gpt-4o-mini", instructions="You execute travel plans. Book the items listed.")
+
+    builder = WorkflowBuilder()
+    builder.add_executor(AgentExecutor("planner", planner))
+    builder.add_executor(AgentExecutor("booker", executor_agent))
+    builder.add_edge("planner", "booker")
+    workflow = builder.build()
+
+    # Evaluate with per-agent breakdown
+    local = LocalEvaluator(is_nonempty, keyword_check("plan", "trip"))
+
+    results = await evaluate_workflow(
+        workflow=workflow,
+        queries=["Plan a weekend trip to Paris"],
+        evaluators=local,
+    )
+
+    for r in results:
+        print(f"{r.provider}: {r.passed}/{r.total} passed (overall)")
+        for agent_name, sub in r.sub_results.items():
+            print(f"  {agent_name}: {sub.passed}/{sub.total}")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())