Wire operation_context into async client User-Agent header

Mirrors sync _ODataClient: reads config.operation_context in __init__ and
appends user_agent_context as a parenthesized comment to the User-Agent header.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Abel Milash

src/PowerPlatform/Dataverse/aio/data/_async_odata.py

@@ -79,6 +79,8 @@ def __init__(
             session=session,
             logger=self._http_logger,
         )
+        ctx_obj = self.config.operation_context
+        self._operation_context = ctx_obj.user_agent_context if ctx_obj else None
         # Prevents concurrent coroutines from racing through the picklist TTL check
         # and issuing redundant metadata fetches.
         self._picklist_cache_lock: asyncio.Lock = asyncio.Lock()
@@ -97,13 +99,14 @@ async def _headers(self) -> Dict[str, str]:
         """Build standard OData headers with bearer auth."""
         scope = f"{self.base_url}/.default"
         token = (await self.auth._acquire_token(scope)).access_token
+        ua = f"{_USER_AGENT} ({self._operation_context})" if self._operation_context else _USER_AGENT
         return {
             "Authorization": f"Bearer {token}",
             "Accept": "application/json",
             "Content-Type": "application/json",
             "OData-MaxVersion": "4.0",
             "OData-Version": "4.0",
-            "User-Agent": _USER_AGENT,
+            "User-Agent": ua,
         }
 
     async def _raw_request(self, method: str, url: str, **kwargs) -> aiohttp.ClientResponse:

tests/unit/aio/data/test_async_odata_internal.py

@@ -1793,3 +1793,33 @@ async def test_build_list_with_count(self):
         _seed_cache(client)
         req = await client._build_list("account", count=True)
         assert "$count=true" in req.url
+
+
+class TestAsyncOperationContextUserAgent:
+    """User-Agent header reflects operation_context on the async client."""
+
+    async def test_default_user_agent_unchanged(self):
+        from PowerPlatform.Dataverse.aio.data._async_odata import _USER_AGENT
+        client = _make_client()
+        headers = await client._headers()
+        assert headers["User-Agent"] == _USER_AGENT
+
+    async def test_operation_context_appended(self):
+        from PowerPlatform.Dataverse.aio.data._async_odata import _USER_AGENT
+        from PowerPlatform.Dataverse.core.config import DataverseConfig, OperationContext
+        ctx_str = "app=dataverse-skills/1.2.1;agent=claude-code"
+        config = DataverseConfig(operation_context=OperationContext(user_agent_context=ctx_str))
+        auth = MagicMock()
+        auth._acquire_token = AsyncMock(return_value=MagicMock(access_token="test-token"))
+        client = _AsyncODataClient(auth, "https://example.crm.dynamics.com", config=config)
+        headers = await client._headers()
+        assert headers["User-Agent"] == f"{_USER_AGENT} ({ctx_str})"
+
+    async def test_none_context_no_parentheses(self):
+        from PowerPlatform.Dataverse.core.config import DataverseConfig
+        config = DataverseConfig(operation_context=None)
+        auth = MagicMock()
+        auth._acquire_token = AsyncMock(return_value=MagicMock(access_token="test-token"))
+        client = _AsyncODataClient(auth, "https://example.crm.dynamics.com", config=config)
+        headers = await client._headers()
+        assert "(" not in headers["User-Agent"]