chore: initial project setup with backend, frontend, and infrastructure

Add complete NexaPantry application structure including:
- Docker Compose configuration with PostgreSQL, Redis, FastAPI backend, worker, frontend and Caddy
- Environment configuration template with database, auth, and service settings
- GitHub Actions CI workflow for backend/frontend linting, testing, auditing and Docker builds
- AGPL-3.0 license and comprehensive README with setup, development, and security documentation
- Backend

frontend/tailwind.config.js

@@ -0,0 +1,19 @@
+export default {
+  darkMode: 'class',
+  content: ['./index.html', './src/**/*.{ts,tsx}'],
+  theme: {
+    extend: {
+      colors: {
+        pantry: {
+          ink: '#172026',
+          teal: '#0f766e',
+          mint: '#d9f99d',
+          berry: '#be123c',
+          amber: '#d97706'
+        }
+      }
+    }
+  },
+  plugins: []
+};
+