add playwright e2e tests for onboarding, contact tracker

- install playwright, configure for chromium with vite dev server
- add onboarding flow test: redirect, form fill, navigation to prozess
- add contact tracker test: create contact, verify in list
- fix onboarding form navigating to /onboarding instead of /prozess
- fix date rendering crash in contact list (cast datum to text)
- exclude @electric-sql/pglite from vite optimizeDeps (WASM bundle)
- add test-results/, playwright-report/ to .gitignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/features/onboarding/components/onboarding-form.tsx

@@ -30,7 +30,7 @@ export function OnboardingForm() {
 					value.aktueller_schritt,
 				],
 			);
-			navigate({ to: "/onboarding" });
+			navigate({ to: "/prozess" });
 		},
 	});