Initial commit : API Node.js + PostgreSQL + sync service Docker

- API Express/pg connectée à PostgreSQL (converti depuis mssql)
- 8 routes : articles, fournisseurs, commandes, stock, mouvements, performance, schema, sync
- Service sync nightly (mssql → pg, cron 3h00)
- Docker Compose : postgres + api + sync + frpc (tunnel sortant)
- Schéma PostgreSQL 17 tables dans postgres/init.sql

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

sync/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "foirfouille-sync",
+  "version": "1.0.0",
+  "description": "Sync nightly SQL Server → PostgreSQL",
+  "main": "index.js",
+  "license": "ISC",
+  "type": "commonjs",
+  "dependencies": {
+    "mssql": "^12.2.0",
+    "node-cron": "^3.0.3",
+    "pg": "^8.13.3"
+  }
+}