Python: DevUI - Internal Refactor, Conversations API support, and per… (#1235)

* Python: DevUI - Internal Refactor, Conversations API support, and performance improvements

Comprehensive refactor of DevUI package including samples relocation,
frontend reorganization, OpenAI Conversations API support, and critical
performance and code quality improvements.

Key Changes:

Architecture & Organization
- Moved DevUI samples to python/samples/getting_started/devui/
- Consolidated with other framework samples for better discoverability
- Added .env.example files and comprehensive README
- Restructured frontend components into feature-based folders (agent, workflow, gallery, layout)
- Created new OpenAI-compliant message renderers (devui should render oai responses types primarily)

New Features
- Added _conversations.py (467 lines) - Full conversation storage abstraction, replaces the /threads endpoint to better match oai conversations api
- Implements OpenAI Conversations API for thread management, Supports in-memory and extensible storage backends

API Simplification
- Use 'model' field as entity_id (agent/workflow name) instead of extra_body
- Use standard OpenAI 'conversation' field for conversation context.

Performance & Quality Improvements
- Improved context management in MessageMapper with bounded memory (~500KB max)
- Implemented hybrid LRU + cleanup approach to prevent unbounded memory growth
- General QOL improvement - Eliminated ~150 lines of dead/duplicate code, Consolidated helper functions into _utils.py, Extracted magic numbers to module-level constants, Optimized conversation item lookups with index-based approach

Testing
- Added test_conversations.py (13 tests)
- Added test_performance_fixes.py (9 tests)
- Updated existing tests for code consolidation
- 53 tests passing

Impact: 76 files changed: +4,106 insertions, -2,373 deletions
All linting and formatting checks passing. No breaking changes - backward compatible.

Migration: Samples moved to python/samples/getting_started/devui/

* readme lint fixes

* initial support for function approval and minor ui fixes

python/packages/devui/tests/test_discovery.py

@@ -14,9 +14,10 @@ from agent_framework_devui._discovery import EntityDiscovery
 @pytest.fixture
 def test_entities_dir():
     """Use the samples directory which has proper entity structure."""
-    # Get the samples directory relative to the current test file
+    # Get the samples directory from the main python samples folder
     current_dir = Path(__file__).parent
-    samples_dir = current_dir.parent / "samples"
+    # Navigate to python/samples/getting_started/devui
+    samples_dir = current_dir.parent.parent.parent / "samples" / "getting_started" / "devui"
     return str(samples_dir.resolve())
 
 
@@ -66,6 +67,58 @@ async def test_empty_directory():
         assert len(entities) == 0
 
 
+async def test_discovery_accepts_agents_with_only_run():
+    """Test that discovery accepts agents with only run() method."""
+    import tempfile
+    from pathlib import Path
+
+    with tempfile.TemporaryDirectory() as temp_dir:
+        temp_path = Path(temp_dir)
+
+        # Create agent with only run() method
+        agent_dir = temp_path / "non_streaming_agent"
+        agent_dir.mkdir()
+
+        init_file = agent_dir / "__init__.py"
+        init_file.write_text("""
+from agent_framework import AgentRunResponse, AgentThread, ChatMessage, Role, TextContent
+
+class NonStreamingAgent:
+    id = "non_streaming"
+    name = "Non-Streaming Agent"
+    description = "Agent without run_stream"
+
+    @property
+    def display_name(self):
+        return self.name
+
+    async def run(self, messages=None, *, thread=None, **kwargs):
+        return AgentRunResponse(
+            messages=[ChatMessage(
+                role=Role.ASSISTANT,
+                contents=[TextContent(text="response")]
+            )],
+            response_id="test"
+        )
+
+    def get_new_thread(self, **kwargs):
+        return AgentThread()
+
+agent = NonStreamingAgent()
+""")
+
+        discovery = EntityDiscovery(str(temp_path))
+        entities = await discovery.discover_entities()
+
+        # Should discover the non-streaming agent
+        agents = [e for e in entities if e.type == "agent"]
+        assert len(agents) == 1
+        # ID is auto-generated, just check it exists and starts with agent_
+        assert agents[0].id.startswith("agent_")
+        assert agents[0].name == "Non-Streaming Agent"
+        assert not agents[0].metadata.get("has_run_stream")
+
+
 if __name__ == "__main__":
     # Simple test runner
     async def run_tests():