Python: Foundry hosted agent V2 (#5379)

* Python: Wrapper + Samples 1st (#5177)

* Experiment

* Update dependency and add non streaming

* Add more samples

* Rename samples

* Add invocations

* Comments 1

* Comments 2

* Comments 3

* Improve README

* Add local shell sample

* WIP: Add eval and memory samples

* Update user agent prefix

* Update user agent prefix doc

* Update dependency (#5215)

* Add tests and more content types (#5235)

* Add tests

* fix tests and sample

* Fix formatting

* Remove function approval contents

* Python: Refine samples and upgrade packages (#5261)

* Refine samples and upgrade pacakges

* Upgrade to a new package that fixes a bug

* Update model env var

* Move samples (#5281)

* Python: Upgrade agentserver packages (#5284)

* Upgrade agentserver packages

* Fix new types

* Python: Add special handling for workflows (#5298)

* Add special handling for workflows

* Address comments

* Improve samples (#5372)

* Python: Add more types (#5378)

* Add more type supports

* Upgrade packages

* Remove TODOs in README

* Fix README

* Comments and mypy

* User agent scoped

* Fix README

* Fix pre commit

* Fix pre commit 2

* Fix pre commit 3

* Fix pre commit 4

* Fix pre commit 5

* Fix pre commit 6

* Add azure-monitor-opentelemetry to dev deps

Fixes Samples & Markdown CI failure. The PR's new transitive dep on
azure-monitor-opentelemetry-exporter (via azure-ai-agentserver-core) makes
pyright resolve the azure.monitor.opentelemetry namespace, flipping the
check_md_code_blocks diagnostic for `configure_azure_monitor` from
reportMissingImports (filtered) to reportAttributeAccessIssue (not filtered).
Installing the umbrella azure-monitor-opentelemetry package in dev makes
pyright resolve the symbol correctly, matching the install guidance the
observability README already gives users.

---------

Co-authored-by: Evan Mattson <evan.mattson@microsoft.com>

python/packages/core/tests/core/test_telemetry.py

@@ -8,6 +8,7 @@ from agent_framework import (
     USER_AGENT_TELEMETRY_DISABLED_ENV_VAR,
     prepend_agent_framework_to_user_agent,
 )
+from agent_framework._telemetry import user_agent_prefix
 
 # region Test constants
 
@@ -96,3 +97,56 @@ def test_modifies_original_dict():
 
     assert result is headers  # Same object
     assert "User-Agent" in headers
+
+
+# region Test user_agent_prefix context manager
+
+
+def test_user_agent_prefix_adds_prefix():
+    """Test that the context manager adds a prefix within its scope."""
+    with user_agent_prefix("test-host"):
+        result = prepend_agent_framework_to_user_agent()
+        assert result["User-Agent"].startswith("test-host/")
+        assert AGENT_FRAMEWORK_USER_AGENT in result["User-Agent"]
+
+    # Prefix is removed after exiting the context
+    result = prepend_agent_framework_to_user_agent()
+    assert result["User-Agent"] == AGENT_FRAMEWORK_USER_AGENT
+
+
+def test_user_agent_prefix_ignores_duplicates():
+    """Test that duplicate prefixes are not added within nested scopes."""
+    with user_agent_prefix("test-host"), user_agent_prefix("test-host"):
+        result = prepend_agent_framework_to_user_agent()
+        assert result["User-Agent"].count("test-host") == 1
+
+
+def test_user_agent_prefix_ignores_empty():
+    """Test that empty strings are not added as prefixes."""
+    with user_agent_prefix(""):
+        result = prepend_agent_framework_to_user_agent()
+        assert result["User-Agent"] == AGENT_FRAMEWORK_USER_AGENT
+
+
+def test_user_agent_prefix_restores_on_exit():
+    """Test that prefixes are fully restored after the context manager exits."""
+    with user_agent_prefix("test-host"):
+        pass
+    result = prepend_agent_framework_to_user_agent()
+    assert result["User-Agent"] == AGENT_FRAMEWORK_USER_AGENT
+
+
+def test_user_agent_prefix_nesting():
+    """Test that nested context managers compose prefixes correctly."""
+    with user_agent_prefix("outer"):
+        with user_agent_prefix("inner"):
+            result = prepend_agent_framework_to_user_agent()
+            assert "outer" in result["User-Agent"]
+            assert "inner" in result["User-Agent"]
+        # Inner prefix removed
+        result = prepend_agent_framework_to_user_agent()
+        assert "outer" in result["User-Agent"]
+        assert "inner" not in result["User-Agent"]
+    # Both removed
+    result = prepend_agent_framework_to_user_agent()
+    assert result["User-Agent"] == AGENT_FRAMEWORK_USER_AGENT