test: add core e2e fixtures and specs

Co-authored-by: Amruth Pillai <im.amruth@gmail.com>

package.json

@@ -51,11 +51,13 @@
 		"@testing-library/react": "^16.3.2",
 		"@testing-library/user-event": "^14.6.1",
 		"@types/node": "^25.9.3",
+		"@types/pg": "^8.20.0",
 		"@vitest/coverage-v8": "^4.1.9",
 		"happy-dom": "^20.10.5",
 		"knip": "^6.17.1",
 		"lefthook": "^2.1.9",
 		"npm-check-updates": "^22.2.3",
+		"pg": "^8.21.0",
 		"turbo": "^2.9.18",
 		"typescript": "^6.0.3",
 		"vitest": "^4.1.9"