chore(backend): address deprecated dependencies in test stack

- Updated jest ecosystem to v30.x in backend/package.json
- Added controlled overrides for test-exclude to remove inflight@1.0.6 and glob@7.2.3
- Updated README.md with deprecation handling procedures and debugging steps
- Modified .kilo/plans/1779643125894-lucky-island.md to document systematic approach for dependency management

backend/package.json

@@ -48,7 +48,7 @@
     "@nestjs/testing": "^11.1.19",
     "@types/bcryptjs": "^2.4.6",
     "@types/express": "^5.0.5",
-    "@types/jest": "^29.5.14",
+    "@types/jest": "^30.0.0",
     "@types/multer": "^1.4.12",
     "@types/node": "^22.19.19",
     "@types/passport-jwt": "^4.0.1",
@@ -58,11 +58,14 @@
     "@typescript-eslint/eslint-plugin": "^8.46.2",
     "@typescript-eslint/parser": "^8.46.2",
     "eslint": "^9.38.0",
-    "jest": "^29.7.0",
+    "jest": "^30.4.2",
     "supertest": "^7.2.2",
-    "ts-jest": "^29.2.6",
+    "ts-jest": "^29.4.11",
     "typescript": "^5.4.5"
   },
+  "overrides": {
+    "test-exclude": "^8.0.0"
+  },
   "jest": {
     "preset": "ts-jest",
     "testEnvironment": "node",