feat: add web testing foundation with infra-backed suites (#349)

* feat: add web test framework with infra-backed suites

* fix: honor DATABASE_URL env in integration prepare script

* fix: apply web test review feedback

* fix: streamline web test infra lifecycle and workflow scope

apps/web/vitest.integration.config.ts

@@ -0,0 +1,17 @@
+import { defineConfig, mergeConfig } from "vitest/config";
+import baseConfig from "./vitest.config";
+
+export default mergeConfig(
+  baseConfig,
+  defineConfig({
+    test: {
+      include: ["src/**/*.integration.test.ts"],
+      pool: "forks",
+      poolOptions: {
+        forks: {
+          singleFork: true,
+        },
+      },
+    },
+  }),
+);