fix(smoke): use azure-pipelines.yml URI to match AzDO schema glob

The AzDO schema is only applied by yaml-language-server when the file
URI matches the configured globs (azure-pipelines.yml / *.yaml). The
smoke test was using 'plain-pipeline.yml' which never matched, causing
test [8] to always return 0 completions.

Also increased didOpen → completion sleep from 0.8s to 1.5s to give
yaml-ls time to parse the 1.6MB AzDO schema JSON.

scripts/smoke_test_completions.py

@@ -391,7 +391,7 @@ async def check_yaml_template_completion(ws: aiohttp.ClientWebSocketResponse) ->
 async def check_azdo_task_completion(ws: aiohttp.ClientWebSocketResponse) -> None:
     """Cursor after '- task: ' — expect AzDO task completions from schema."""
     print("\n[8] AzDO task completion  (- task: <cursor>@azdo-schema)")
-    task_doc_uri = "file:///tmp/smoke_test/plain-pipeline.yml"
+    task_doc_uri = "file:///tmp/smoke_test/azure-pipelines.yml"
     task_doc = "steps:\n  - task: "
     await ws.send_bytes(_frame({
         "jsonrpc": "2.0",
@@ -405,7 +405,7 @@ async def check_azdo_task_completion(ws: aiohttp.ClientWebSocketResponse) -> Non
             }
         },
     }))
-    await asyncio.sleep(0.8)
+    await asyncio.sleep(1.5)  # yaml-ls needs time to parse 1.6MB AzDO schema
     lines = task_doc.split("\n")
     last_line = len(lines) - 1
     last_char = len(lines[-1])