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/agent_framework_devui/models/_openai_custom.py

@@ -390,7 +390,7 @@ class MetaResponse(BaseModel):
     """Backend runtime/language - 'python' or 'dotnet' for deployment guides and feature availability."""
 
     capabilities: dict[str, bool] = {}
-    """Server capabilities (e.g., tracing, openai_proxy)."""
+    """Server capabilities (e.g., instrumentation, openai_proxy)."""
 
     auth_required: bool = False
     """Whether the server requires Bearer token authentication."""