Python: Fix store=False not overriding client default

[TaoChenOSU]

Motivation and Context

Closes #4488

Description

Fixes the bug where runtime store=False option doesn't take precedence over client default option.

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.

[Copilot]

Pull request overview

Fixes a bug in the Python agent runtime where store=False provided via agent/runtime options does not correctly take precedence over client defaults (e.g., STORES_BY_DEFAULT=True), impacting whether local history storage is injected.

Changes:

• Merge agent default_options with runtime options in _prepare_run_context so runtime options take precedence.
• Simplify the InMemoryHistoryProvider auto-injection condition using store + STORES_BY_DEFAULT.
• Update/expand unit tests around STORES_BY_DEFAULT / store behaviors and refresh python/uv.lock dependency pins.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
python/packages/core/agent_framework/_agents.py	Merges default + runtime options earlier and adjusts store/STORES_BY_DEFAULT logic for local history injection.
python/packages/core/tests/core/test_agents.py	Adds/adjusts tests for storage injection behavior and reformats some existing tests.
python/uv.lock	Updates locked dependency versions (filelock, fonttools, kiwisolver, posthog, prek, setuptools).

Comments suppressed due to low confidence (1)

python/packages/core/tests/core/test_agents.py:1589

• The regression this PR targets (agent-level default_options={"store": False} should override a client with STORES_BY_DEFAULT=True) isn’t directly covered by the added tests. Current coverage only asserts runtime options={"store": False}. Please add a test where client.STORES_BY_DEFAULT=True, the agent is constructed with default_options={"store": False}, run() is called without passing options, and InMemoryHistoryProvider is injected.

async def test_stores_by_default_with_store_false_injects_inmemory(
    client: SupportsChatGetResponse,
) -> None:
    """Client with STORES_BY_DEFAULT=True but store=False should still inject InMemoryHistoryProvider."""
    from agent_framework._sessions import InMemoryHistoryProvider

    client.STORES_BY_DEFAULT = True  # type: ignore[attr-defined]

    agent = Agent(client=client)
    session = agent.create_session()

    await agent.run("Hello", session=session, options={"store": False})

[Copilot]

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated 3 comments.

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
packages/core/agent_framework
_agents.py	352	42	88%	457, 461, 525, 943, 981, 999, 1098–1102, 1176, 1313, 1331, 1333, 1348, 1354, 1393, 1395, 1404–1407, 1410–1411, 1416, 1418, 1424–1425, 1437, 1439–1440, 1448–1449, 1454–1456, 1464–1465, 1467, 1472, 1474
TOTAL	22685	2578	88%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
4947	20 💤	0 ❌	0 🔥	1m 20s ⏱️