refactor: remove Ollama integration and unused AI configuration

- Remove src/models/ollama_client.py, embeddings.py, embeddings_ollama.py
- Remove model aliases and AI config from settings (both config.py files)
- Update health endpoints to only check database connectivity
- Update tests to reflect database-only health checks
- Update README, .env.example, and OIDC docstrings

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/test_health.py

@@ -80,24 +80,24 @@ class TestFullHealthCheck:
     """Test /health/full endpoint."""
 
     @patch("src.shared.database.Database.health_check")
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_full_health_returns_503_when_unhealthy(self, mock_get_ollama, mock_db_health, client):
-        """Full health should return 503 when Ollama unhealthy."""
-        mock_client = AsyncMock()
-        mock_client.health_check.return_value = False
-        mock_get_ollama.return_value = mock_client
+    def test_full_health_returns_200_when_healthy(self, mock_db_health, client):
+        """Full health should return 200 when database is healthy."""
         mock_db_health.return_value = True
 
+        response = client.get("/health/full")
+        assert response.status_code == 200
+
+    @patch("src.shared.database.Database.health_check")
+    def test_full_health_returns_503_when_unhealthy(self, mock_db_health, client):
+        """Full health should return 503 when database is unhealthy."""
+        mock_db_health.return_value = False
+
         response = client.get("/health/full")
         assert response.status_code == 503
 
     @patch("src.shared.database.Database.health_check")
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_full_health_returns_components_status(self, mock_get_ollama, mock_db_health, client):
+    def test_full_health_returns_components_status(self, mock_db_health, client):
         """Full health should return component status."""
-        mock_client = AsyncMock()
-        mock_client.health_check.return_value = False
-        mock_get_ollama.return_value = mock_client
         mock_db_health.return_value = True
 
         response = client.get("/health/full")
@@ -105,63 +105,32 @@ class TestFullHealthCheck:
 
         assert "status" in data
         assert "components" in data
-        assert "ollama" in data["components"]
         assert "database" in data["components"]
         assert "response_time_ms" in data
 
     @patch("src.shared.database.Database.health_check")
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_full_health_handles_list_models_error(self, mock_get_ollama, mock_db_health, client):
-        """Full health should handle list_models errors."""
-        mock_client = AsyncMock()
-        mock_client.health_check.return_value = True
-        mock_client.list_models.side_effect = Exception("Connection error")
-        mock_get_ollama.return_value = mock_client
-        mock_db_health.return_value = True
+    def test_full_health_handles_database_error(self, mock_db_health, client):
+        """Full health should handle database errors gracefully."""
+        mock_db_health.side_effect = Exception("Connection error")
 
         response = client.get("/health/full")
         data = response.json()
 
-        # Should report error in component status
-        assert "ollama" in data["components"]
-
-    @patch("src.shared.database.Database.health_check")
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_full_health_handles_health_check_exception(self, mock_get_ollama, mock_db_health, client):
-        """Full health should handle health check exceptions gracefully."""
-        mock_client = AsyncMock()
-        # Return False instead of raising exception to test unhealthy path
-        mock_client.health_check.return_value = False
-        mock_get_ollama.return_value = mock_client
-        mock_db_health.return_value = True
-
-        response = client.get("/health/full")
-        # Should return 503 for unhealthy
         assert response.status_code == 503
-        data = response.json()
         assert data["status"] == "unhealthy"
+        assert "error" in data["components"]["database"]
 
 
 class TestDiagnosticsEndpoint:
     """Test /health/diagnostics endpoint."""
 
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_diagnostics_returns_200(self, mock_get_ollama, client):
+    def test_diagnostics_returns_200(self, client):
         """Diagnostics should return 200."""
-        mock_client = AsyncMock()
-        mock_client.health_check.return_value = True
-        mock_get_ollama.return_value = mock_client
-
         response = client.get("/health/diagnostics")
         assert response.status_code == 200
 
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_diagnostics_returns_service_info(self, mock_get_ollama, client):
+    def test_diagnostics_returns_service_info(self, client):
         """Diagnostics should return service information."""
-        mock_client = AsyncMock()
-        mock_client.health_check.return_value = True
-        mock_get_ollama.return_value = mock_client
-
         response = client.get("/health/diagnostics")
         data = response.json()
 
@@ -169,54 +138,17 @@ class TestDiagnosticsEndpoint:
         assert "name" in data["service"]
         assert "version" in data["service"]
 
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_diagnostics_returns_components(self, mock_get_ollama, client):
-        """Diagnostics should return component details."""
-        mock_client = AsyncMock()
-        mock_client.health_check.return_value = True
-        mock_get_ollama.return_value = mock_client
-
-        response = client.get("/health/diagnostics")
-        data = response.json()
-
-        assert "components" in data
-        assert "ollama" in data["components"]
-
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_diagnostics_returns_configuration(self, mock_get_ollama, client):
+    def test_diagnostics_returns_configuration(self, client):
         """Diagnostics should return configuration info."""
-        mock_client = AsyncMock()
-        mock_client.health_check.return_value = True
-        mock_get_ollama.return_value = mock_client
-
         response = client.get("/health/diagnostics")
         data = response.json()
 
         assert "configuration" in data
 
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_diagnostics_returns_response_time(self, mock_get_ollama, client):
+    def test_diagnostics_returns_response_time(self, client):
         """Diagnostics should return response time."""
-        mock_client = AsyncMock()
-        mock_client.health_check.return_value = True
-        mock_get_ollama.return_value = mock_client
-
         response = client.get("/health/diagnostics")
         data = response.json()
 
         assert "response_time_ms" in data
         assert isinstance(data["response_time_ms"], int)
-
-    @patch("src.models.ollama_client.get_ollama_client")
-    def test_diagnostics_handles_ollama_error(self, mock_get_ollama, client):
-        """Diagnostics should handle Ollama connection errors."""
-        mock_client = AsyncMock()
-        mock_client.health_check.side_effect = Exception("Connection refused")
-        mock_get_ollama.return_value = mock_client
-
-        response = client.get("/health/diagnostics")
-        data = response.json()
-
-        # Should still return 200 with error info
-        assert response.status_code == 200
-        assert "error" in data["components"]["ollama"]