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/templates/label_print.html

@@ -0,0 +1,89 @@
+<!doctype html>
+<html lang="ro">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>Etichetă {{ payload.fields.recipe_code }} · {{ payload.fields.total_weight }} {{ payload.fields.unit }}</title>
+  <style>
+    @page { size: {{ payload.template.width_mm }}mm {{ payload.template.height_mm }}mm; margin: 0; }
+    * { box-sizing: border-box; }
+    html, body { margin: 0; padding: 0; background: #e9edf1; }
+    .preview-bar {
+      position: sticky; top: 0; z-index: 2;
+      display: flex; align-items: center; gap: 12px;
+      padding: 10px 16px; background: #0f172a; color: #fff;
+      font: 14px/1.4 system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
+    }
+    .preview-bar button {
+      margin-left: auto; padding: 8px 16px; border: 0; border-radius: 6px;
+      background: #14b8a6; color: #04201d; font-weight: 700; cursor: pointer;
+    }
+    .preview-stage { padding: 24px; display: flex; justify-content: center; }
+    .label-sheet {
+      width: {{ payload.template.width_mm }}mm;
+      height: {{ payload.template.height_mm }}mm;
+      background: #fff;
+      overflow: hidden;
+      box-shadow: 0 6px 24px rgba(15, 23, 42, .18);
+    }
+    {{ payload.css|safe }}
+    @media print {
+      html, body { background: #fff; }
+      .preview-bar, .preview-stage { padding: 0; }
+      .preview-bar { display: none !important; }
+      .label-sheet { box-shadow: none; margin: 0; }
+    }
+  </style>
+</head>
+<body>
+  {% if preview %}
+  <div class="preview-bar">
+    <strong>Previzualizare șablon</strong>
+    <span>{{ payload.template.name }} · {{ payload.template.width_mm|weight }} × {{ payload.template.height_mm|weight }} mm</span>
+    <button type="button" onclick="window.print()">Tipărește previzualizarea</button>
+  </div>
+  {% endif %}
+
+  <div class="preview-stage">
+    <div class="label-sheet" id="label-sheet">
+      {{ payload.html|safe }}
+    </div>
+  </div>
+
+  <script id="label-payload" type="application/json">{{ payload|tojson }}</script>
+  <script src="{{ url_for('static', filename='js/vendor/qz-tray.js') }}"></script>
+  <script src="{{ url_for('static', filename='js/qz-print.js') }}"></script>
+  <script>
+    (function () {
+      var payload = JSON.parse(document.getElementById('label-payload').textContent);
+      var auto = {{ 'true' if auto else 'false' }};
+      var preview = {{ 'true' if preview else 'false' }};
+
+      function acknowledge() {
+        if (preview) return;
+        try {
+          fetch(payload.ack_url, { method: 'POST', headers: { 'Accept': 'application/json' } });
+        } catch (e) { /* tipărirea a reușit; confirmarea este auxiliară */ }
+      }
+
+      function doPrint() {
+        if (window.CantarirePrint && typeof window.CantarirePrint.print === 'function') {
+          Promise.resolve(window.CantarirePrint.print(payload)).then(function (result) {
+            if (result && result.method === 'qz') acknowledge();
+          }, function (err) {
+            console.error('Tipărirea QZ Tray a eșuat:', err);
+          });
+          return;
+        }
+        window.print();
+        acknowledge();
+      }
+
+      window.addEventListener('load', function () {
+        if (!auto) return;
+        setTimeout(doPrint, 120);
+      });
+    })();
+  </script>
+</body>
+</html>