Initial scaffold: full-stack RackMapper application

Complete project scaffold with working auth, REST API, Prisma/SQLite
schema, Docker config, and React frontend for both Rack Planner and
Service Mapper modules. Both server and client pass TypeScript strict
mode with zero errors. Initial migration applied.

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

client/postcss.config.js

@@ -0,0 +1,6 @@
+export default {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+};