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>

vite.config.ts

@@ -19,6 +19,9 @@ export default defineConfig({
 			manifest: false,
 		}),
 	],
+	optimizeDeps: {
+		exclude: ["@electric-sql/pglite"],
+	},
 	resolve: {
 		alias: {
 			"@": path.resolve(__dirname, "./src"),