feat: configure Jest testing infrastructure

- Update Jest config with module name mapping for uuid and node-fetch
- Add Babel transform for mixed JS/TS support
- Configure transformIgnorePatterns for ES modules
- Add comprehensive test mocks for uuid and node-fetch
- Setup import.meta environment variables for Jest compatibility
- Increase test timeout to 30 seconds for integration tests

jest.config.json

@@ -17,10 +17,16 @@
   ],
   "coverageDirectory": "coverage",
   "coverageReporters": ["text", "lcov", "html"],
-  "moduleNameMapping": {
-    "^@/(.*)$": "<rootDir>/$1"
+  "moduleNameMapper": {
+    "^@/(.*)$": "<rootDir>/$1",
+    "^uuid$": "<rootDir>/tests/__mocks__/uuid.js",
+    "^node-fetch$": "<rootDir>/tests/__mocks__/node-fetch.js"
   },
   "transform": {
-    "^.+\\.tsx?$": "ts-jest"
-  }
+    "^.+\\.tsx?$": "ts-jest",
+    "^.+\\.jsx?$": "babel-jest"
+  },
+  "transformIgnorePatterns": ["node_modules/(?!(@jest/transform|uuid|node-fetch)/)"],
+  "testTimeout": 30000,
+  "moduleFileExtensions": ["ts", "tsx", "js", "jsx", "json", "node"]
 }