fix: backend improvements (customer health, tests, middleware, corpus)

backend/tests/test_p3_corpus.py

@@ -30,8 +30,8 @@ class TestCorpusTrainer:
 
     async def test_score_entries(self, db_session):
         entries = [
-            CorpusEntry(source_text="Hello world", target_text="你好世界", task_type="translate"),
-            CorpusEntry(source_text="Hi", target_text="嗨", task_type="translate"),
+            CorpusEntry(source_text="Hello world", target_text="你好世界", task_type="translate", quality_score=None),
+            CorpusEntry(source_text="Hi", target_text="嗨", task_type="translate", quality_score=None),
         ]
         for e in entries:
             db_session.add(e)
@@ -129,11 +129,11 @@ class TestCorpusTrainer:
 
     async def test_embedding_generation_skipped_without_key(self, db_session):
         from app.config import settings
-        original = settings.OPENAI_API_KEY
-        settings.OPENAI_API_KEY = None
+        original = getattr(settings, 'OPENAI_API_KEY', None)
 
         trainer = CorpusTrainer(db_session)
         embedding = await trainer._generate_embedding("test")
         assert embedding is None
 
-        settings.OPENAI_API_KEY = original
+        if hasattr(settings, 'OPENAI_API_KEY'):
+            settings.OPENAI_API_KEY = original