test(integration): add real-stack integration test suite with PGlite

- PGlite (in-memory WASM Postgres) hosted in a child process, exposed
  via TCP socket; real migrations applied with prisma migrate deploy
- Vitest harness (vitest.integration.config.ts, global-setup spawns
  PGlite + built Nuxt server, per-test TRUNCATE, factories, cookie-jar
  API client); no mocks, zero production code changes
- 50 tests across auth, hunt, team, submit, review, showcase, diashow
  incl. SuperJSON envelope check; *.itest.ts keeps bun test untouched
- CI: parallel unit + integration jobs in .github/workflows/test.yml
- tests/ covered by nuxt typecheck via tests/tsconfig.json reference

tests/tsconfig.json

@@ -0,0 +1,33 @@
+{
+  // Integration tests + helpers. Picked up by `nuxt typecheck` through the
+  // reference in the root tsconfig.json. Mirrors the options of the
+  // Nuxt-generated tsconfigs, minus noUncheckedIndexedAccess (tests assert
+  // on indexed access all the time).
+  "compilerOptions": {
+    "paths": {
+      "~~": [".."],
+      "~~/*": ["../*"],
+      "#shared": ["../shared"],
+      "#shared/*": ["../shared/*"]
+    },
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "target": "ESNext",
+    "resolveJsonModule": true,
+    "moduleDetection": "force",
+    "isolatedModules": true,
+    "verbatimModuleSyntax": true,
+    "strict": true,
+    "forceConsistentCasingInFileNames": true,
+    "noImplicitOverride": true,
+    "module": "preserve",
+    "noEmit": true,
+    "types": ["node"],
+    "moduleResolution": "Bundler",
+    "useDefineForClassFields": true,
+    "noImplicitThis": true,
+    "allowSyntheticDefaultImports": true
+  },
+  "include": ["./**/*.ts", "../vitest.integration.config.ts"],
+  "exclude": ["../node_modules"]
+}