Python: Add default InMemoryHistoryProvider when workflow context providers are unset

[eavanvalkenburg]

Summary

• default WorkflowAgent to an InMemoryHistoryProvider("memory") when no context providers are configured
• preserve explicitly provided context providers without adding defaults
• add workflow agent tests in existing suite to cover default injection and explicit-provider behavior

Validation

• uv run ruff format packages/core/agent_framework/_workflows/_agent.py packages/core/tests/workflow/test_workflow_agent.py
• uv run ruff check packages/core/agent_framework/_workflows/_agent.py packages/core/tests/workflow/test_workflow_agent.py
• uv run --directory packages/core pytest tests/workflow/test_workflow_agent.py -k 'default_history_provider or explicit_context_providers or session_conversation_history_included_in_workflow_run or session_conversation_history_included_in_workflow_stream' -q

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
packages/core/agent_framework/_workflows
_agent.py	346	68	80%	65, 73–79, 115–116, 206, 250, 306, 352–353, 359–360, 366, 368, 373, 433–434, 443, 450, 476, 509–511, 513, 515, 517, 522, 527, 574, 604, 621, 660–663, 669, 675, 679–680, 683–689, 693–694, 700, 761, 768, 774–775, 786, 818, 825, 846, 855, 859, 861–863, 870
TOTAL	20475	3243	84%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
3920	225 💤	0 ❌	0 🔥	1m 11s ⏱️

[Copilot]

Pull request overview

This pull request adds automatic injection of a default InMemoryHistoryProvider to WorkflowAgent when no context providers are configured, ensuring conversation history is maintained by default without requiring explicit provider configuration.

Changes:

• Add eager default provider injection in WorkflowAgent.__init__() when context_providers is None or empty
• Add comprehensive test coverage for default injection behavior and explicit provider preservation

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
python/packages/core/agent_framework/_workflows/_agent.py	Adds default InMemoryHistoryProvider("memory") injection in constructor when no context providers are configured, using eager injection pattern
python/packages/core/tests/workflow/test_workflow_agent.py	Adds two tests: one verifying default history provider injection and conversation history preservation, another verifying explicit providers are not modified