fix: Handle charset parameter in SSE Content-Type header test

The SSE endpoint returns 'text/event-stream; charset=utf-8' but the test
was checking for an exact match. Update the test to use startswith() to
handle the charset parameter correctly.

tests/test_api_jobs.py

@@ -67,6 +67,7 @@ class TestJobStreaming:
         response = test_client.get("/api/v1/jobs/stream/test-job-id")
         
         if response.status_code == 200:
-            # Check Content-Type for SSE
-            assert response.headers.get("content-type") == "text/event-stream"
+            # Check Content-Type for SSE (may include charset parameter)
+            content_type = response.headers.get("content-type", "")
+            assert content_type.startswith("text/event-stream")