Python: Improve DevUI, add Context Inspector view as new tab under traces (#2742)

* Improve DevUI, add Context Inspector view as new tab under traces

* fix mypy errors

* fix: Handle stale MCP connections in DevUI executor

MCP tools can become stale when HTTP streaming responses end - the underlying
stdio streams close but `is_connected` remains True. This causes subsequent
requests to fail with `ClosedResourceError`.

Add `_ensure_mcp_connections()` to detect and reconnect stale MCP tools before
agent execution. This is a workaround for an upstream Agent Framework issue
where connection state isn't properly tracked.

Fixes MCP tools failing on second HTTP request in DevUI.

fixes  #1476 #1515 #2865

* fix #1572 report import dependency errors more clearly

* Ensure there is streaming toggle where users can select streaming vs non streaming mode in devui . Fixes .NET: [Python] DevUI tool call rendering in non-streaming mode?

* remove unused dead code

* improve ux - workflows with agents show a chat component in execution timelien, also ensure magentic final output shows correctly

* update ui build

* update devui to use instrumentation instead of tracing, other instrumentation and type/instance check fixes

python/packages/devui/tests/test_checkpoints.py

@@ -8,8 +8,10 @@ import pytest
 from agent_framework import (
     Executor,
     InMemoryCheckpointStorage,
+    RequestInfoEvent,
     WorkflowBuilder,
     WorkflowContext,
+    WorkflowStatusEvent,
     handler,
     response_handler,
 )
@@ -426,14 +428,11 @@ class TestIntegration:
         # Run workflow until it reaches IDLE_WITH_PENDING_REQUESTS (after checkpoint is created)
         saw_request_event = False
         async for event in test_workflow.run_stream(WorkflowTestData(value="test")):
-            if hasattr(event, "__class__"):
-                if event.__class__.__name__ == "RequestInfoEvent":
-                    saw_request_event = True
-                # Wait for IDLE_WITH_PENDING_REQUESTS status (comes after checkpoint creation)
-                is_status_event = event.__class__.__name__ == "WorkflowStatusEvent"
-                has_pending_status = hasattr(event, "status") and "IDLE_WITH_PENDING_REQUESTS" in str(event.status)
-                if is_status_event and has_pending_status:
-                    break
+            if isinstance(event, RequestInfoEvent):
+                saw_request_event = True
+            # Wait for IDLE_WITH_PENDING_REQUESTS status (comes after checkpoint creation)
+            if isinstance(event, WorkflowStatusEvent) and "IDLE_WITH_PENDING_REQUESTS" in str(event.state):
+                break
 
         assert saw_request_event, "Test workflow should have emitted RequestInfoEvent"