Initial commit: aplicatie de cantarire si etichetare

Aplicatie Flask + SQLite pentru productie alimentara: cantarirea
componentelor unui produs finit si tiparirea etichetei prin QZ Tray.

- produse finite (retete) formate din componente cantarite
- designer vizual de etichete (mm/px, zona sigura, campuri variabile,
  cod QR cu continut din mai multe bucati)
- legare produs finit -> sablon de eticheta
- navigare pe doua taburi: Cantarire / Setari
- administrare: componente, produse finite, sabloane, campuri, istoric
- backup, resetare baza de date, checklist de pregatire, /healthz
- CLI de administrare si serviciu systemd pentru productie
- vendor/syncpulse-scale-bridge (GPL-3.0-or-later) pentru citirea cantarului

cantarire/static/js/vendor/README.md

@@ -0,0 +1,16 @@
+# QZ Tray connector (`qz-tray.js`)
+
+- **Version:** 2.2.4
+- **License:** LGPL-2.1-only (see the header of `qz-tray.js`)
+- **Source:** copied unmodified from
+  `quality_app-v2/app/static/js/qz-tray.js` (Gitea: `ske087/quality_app-v2`).
+- **Local patch:** it **skips the certificate exchange** and connects to the
+  custom QZ Tray service that authenticates with a **pairing key**
+  (`PATCHED` markers around the original `_qz.websocket.connection.sendData({ certificate … })`).
+
+Because the file is a modified LGPL-2.1 library, keep it under
+`static/js/vendor/` and ship this notice plus the license header with it.
+If you later use stock QZ Tray (certificate + signature), set
+`window.CANTARIRE_QZ = { certificateUrl, signatureUrl }` before loading
+`qz-print.js`; `qz-print.js` wires `qz.security.setCertificatePromise` and
+`setSignaturePromise` when those URLs are provided.