Python: Refactor ag-ui to clean up some patterns (#2363)

* Refactor ag-ui to clean up some patterns

* Mypy fixes

* Fix imports, typing, tests, logging.

* Fix test import error

* Fix imports again

* Fix thread handling

python/packages/ag-ui/tests/test_message_hygiene.py

@@ -0,0 +1,53 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from agent_framework import ChatMessage, FunctionCallContent, FunctionResultContent, TextContent
+
+from agent_framework_ag_ui._orchestration._message_hygiene import (
+    deduplicate_messages,
+    sanitize_tool_history,
+)
+
+
+def test_sanitize_tool_history_injects_confirm_changes_result() -> None:
+    messages = [
+        ChatMessage(
+            role="assistant",
+            contents=[
+                FunctionCallContent(
+                    name="confirm_changes",
+                    call_id="call_confirm_123",
+                    arguments='{"changes": "test"}',
+                )
+            ],
+        ),
+        ChatMessage(
+            role="user",
+            contents=[TextContent(text='{"accepted": true}')],
+        ),
+    ]
+
+    sanitized = sanitize_tool_history(messages)
+
+    tool_messages = [
+        msg for msg in sanitized if (msg.role.value if hasattr(msg.role, "value") else str(msg.role)) == "tool"
+    ]
+    assert len(tool_messages) == 1
+    assert str(tool_messages[0].contents[0].call_id) == "call_confirm_123"
+    assert tool_messages[0].contents[0].result == "Confirmed"
+
+
+def test_deduplicate_messages_prefers_non_empty_tool_results() -> None:
+    messages = [
+        ChatMessage(
+            role="tool",
+            contents=[FunctionResultContent(call_id="call1", result="")],
+        ),
+        ChatMessage(
+            role="tool",
+            contents=[FunctionResultContent(call_id="call1", result="result data")],
+        ),
+    ]
+
+    deduped = deduplicate_messages(messages)
+    assert len(deduped) == 1
+    assert deduped[0].contents[0].result == "result data"