infra: add Docker Compose setup for local development

- Configure PostgreSQL 18 and Valkey 9.1 services
- Create multi-stage Dockerfiles for API and Web apps
- Set up pnpm workspace support in container builds
- Configure hot reload via volume mounts for both services
- Add healthchecks for service orchestration
- Support dev/production stage targets (tsx watch vs compiled)

packages/shared/package.json

@@ -2,5 +2,11 @@
   "name": "@glossa/shared",
   "version": "1.0.0",
   "private": true,
-  "type": "module"
+  "type": "module",
+  "scripts": {
+    "build": "tsc"
+  },
+  "exports": {
+    ".": "./src/index.ts"
+  }
 }