chore: add docker-compose, .gitignore and README

Infrastructure files for staging deployment pipeline.
The post-receive hook on the staging server will build and
deploy automatically when PRs are merged to main.

Made-with: Cursor

.gitignore

@@ -0,0 +1,23 @@
+# Environment files — never commit secrets
+.env
+.env.*
+!.env.example
+
+# Next.js
+.next/
+out/
+node_modules/
+
+# Build
+dist/
+build/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*