feat: migrate e2e test infrastructure to @playwright/test

Replace direct playwright dependency with @playwright/test and add
playwright.config.js for centralized test configuration. Update run.sh
to invoke 'npx playwright test' instead of running test files with node.

tests/e2e/package-lock.json

@@ -6,7 +6,22 @@
     "": {
       "name": "porchlight-e2e",
       "dependencies": {
-        "playwright": "^1.52.0"
+        "@playwright/test": "^1.52.0"
+      }
+    },
+    "node_modules/@playwright/test": {
+      "version": "1.58.2",
+      "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.58.2.tgz",
+      "integrity": "sha512-akea+6bHYBBfA9uQqSYmlJXn61cTa+jbO87xVLCWbTqbWadRVmhxlXATaOjOgcBaWU4ePo0wB41KMFv3o35IXA==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright": "1.58.2"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
       }
     },
     "node_modules/fsevents": {