feat(web): scaffold Vite + React + TS SPA with Vitest

Bootstraps the web/ SPA: Vite 6 + React 19 + TypeScript 5.8, Vitest
with jsdom, @testing-library/react, and a green smoke test asserting
the App renders its Collection heading.

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

web/.gitignore

@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?