fix: restore all code deleted/truncated by d2217531 Jules SSRF commit

Commit d2217531 (google-labs-jules SSRF fix) catastrophically deleted
11,500+ lines across 100+ files while fixing an unrelated IMAP issue.

Restored from d2217531^ (pre-bad-commit state):

Deleted files (fully restored):
- app/api/{automation,classification_rules,comments,sharing}.py
- app/middleware/upload_rate_limit.py
- app/tasks/{automation_tasks,classify_document}.py
- app/utils/{automation_hooks,classification_rules}.py
- docs/AppleAppStoreCompliance.md
- frontend/input.css, package.json, package-lock.json, tailwind.config.js
- frontend/static/js/{annotations,claim,comments,sharing}.js
- frontend/templates/{admin_connections,file_annotations,file_summary}.html
- tests/{test_api_files_comprehensive,test_auth_extended,test_sharing,
         test_comments,test_connections,test_imap_profiles,test_api_sessions,
         test_automation,test_classification_rules,test_api_advanced_filters,
         test_api_classification_rules,test_upload_rate_limit,test_api_dropbox,
         test_classify_document,test_comments_ui,test_upload_to_icloud,
         test_api_onedrive_comprehensive,test_frontend_build,test_sentry,
         test_diagnostic,test_database,test_views_dropbox,test_local_auth}.py

Truncated files (content restored):
- app/{auth,config,main,models,celery_worker,database}.py
- app/api/{__init__,api_tokens,diagnostic,dropbox,files,google_drive,
           integrations,local_auth,mobile,onedrive,pipelines,qr_auth,
           settings,url_upload}.py
- app/middleware/upload_rate_limit.py
- app/tasks/upload_to_nextcloud.py
- app/utils/{allowed_types,settings_service,settings_sync,user_scope,webhook}.py
- app/views/{base,dropbox,files,google_drive,onedrive,settings}.py
- docs/{API,AuthenticationSetup,ConfigurationGuide,DatabaseConfiguration,
        DeploymentGuide,DropboxSetup,GoogleDriveSetup,KubernetesDeployment,
        MobileApp,OneDriveSetup,ProductionReadiness,SentrySetup,
        SocialLoginSetup,UserGuide}.md
- frontend/static/{js/upload.js,styles.css}
- frontend/templates/{api_tokens,base,devices,dropbox,dropbox_callback,
                      file_view,files,google_drive,onedrive,onedrive_callback,
                      signup}.html
- frontend/translations/en.json
- migrations/env.py
- tests/{conftest,test_api_integrations,test_api_mobile,test_api_settings,
         test_api_tokens,test_audit_logs,test_duplicates,test_imap_tasks,
         test_setup_wizard,test_views_files_comprehensive}.py

Security fixes kept from post-d2217531 commits:
- app/utils/network.py: DNS SSRF fail-secure fix (06b0fced)
- app/utils/file_operations.py: path traversal fix (1018ea17)
- tests/test_imap_tasks.py: re-applied 4 is_private_ip mock patches

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
Agent-Logs-Url: https://github.com/christianlouis/DocuElevate/sessions/51133dd8-9bec-41ab-aa10-3de753634187

tests/test_database.py

@@ -998,3 +998,49 @@ class TestAlembicUpgrade:
         # Verify head is reachable
         heads = script.get_heads()
         assert len(heads) == 1  # Should be a single linear chain
+
+
+@pytest.mark.unit
+class TestEnginePoolConfiguration:
+    """Tests for database engine pool configuration (pool class and options)."""
+
+    def test_sqlite_engine_uses_null_pool(self):
+        """SQLite engines must use NullPool to prevent QueuePool exhaustion."""
+        from sqlalchemy.pool import NullPool
+
+        from app.database import engine
+
+        # The test environment uses SQLite, so NullPool should be in effect.
+        assert isinstance(engine.pool, NullPool)
+
+    def test_create_engine_sqlite_null_pool(self):
+        """Explicitly create a SQLite engine to confirm NullPool is applied."""
+        from sqlalchemy import create_engine
+        from sqlalchemy.pool import NullPool
+
+        test_engine = create_engine(
+            "sqlite:///:memory:",
+            connect_args={"check_same_thread": False},
+            poolclass=NullPool,
+        )
+        assert isinstance(test_engine.pool, NullPool)
+        test_engine.dispose()
+
+    def test_pool_settings_exist_in_config(self):
+        """Verify that pool tuning settings are exposed through config."""
+        from app.config import settings
+
+        assert hasattr(settings, "db_pool_size")
+        assert hasattr(settings, "db_max_overflow")
+        assert hasattr(settings, "db_pool_timeout")
+        assert hasattr(settings, "db_pool_recycle")
+
+    def test_pool_settings_have_sensible_defaults(self):
+        """Default pool settings should be larger than SQLAlchemy's built-in defaults."""
+        from app.config import settings
+
+        # SQLAlchemy defaults: pool_size=5, max_overflow=10
+        assert settings.db_pool_size >= 10
+        assert settings.db_max_overflow >= 20
+        assert settings.db_pool_timeout >= 30
+        assert settings.db_pool_recycle >= 1800