feat(inventory): dynamic tab badges with real tenant data

- Add /pos/api/inventory/stats endpoint returning counts per tab
- Replace hardcoded badge numbers (4,817, 14, 3, 23) with dynamic values
- Frontend auto-fetches stats on page load and updates badges

pos/blueprints/inventory_bp.py

@@ -809,6 +809,52 @@ def physical_count_approve():
     })
 
 
+# ─── Stats Summary ─────────────────────────────
+
+@inventory_bp.route('/stats', methods=['GET'])
+@require_auth('inventory.view')
+def api_inventory_stats():
+    """Get inventory summary counts for dashboard badges."""
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+    branch_id = getattr(g, 'branch_id', None)
+
+    # Stock count
+    cur.execute("SELECT COUNT(*) FROM inventory WHERE is_active = true AND (branch_id = %s OR %s IS NULL)", (branch_id, branch_id))
+    stock = cur.fetchone()[0]
+
+    # Operations counts by type
+    cur.execute("""
+        SELECT operation_type, COUNT(*) 
+        FROM inventory_operations 
+        WHERE (branch_id = %s OR %s IS NULL)
+        GROUP BY operation_type
+    """, (branch_id, branch_id))
+    op_counts = {row[0]: row[1] for row in cur.fetchall()}
+
+    # Physical counts
+    cur.execute("SELECT COUNT(*) FROM physical_counts WHERE (branch_id = %s OR %s IS NULL)", (branch_id, branch_id))
+    physical = cur.fetchone()[0]
+
+    cur.close()
+    conn.close()
+
+    # Alerts (reuse existing function)
+    conn2 = get_tenant_conn(g.tenant_id)
+    alerts_list = get_alerts(conn2, branch_id)
+    conn2.close()
+
+    return jsonify({
+        'stock': stock,
+        'entradas': op_counts.get('PURCHASE', 0),
+        'salidas': op_counts.get('SALE', 0),
+        'traspasos': op_counts.get('TRANSFER', 0),
+        'ajustes': op_counts.get('ADJUST', 0),
+        'conteos': physical,
+        'alertas': len(alerts_list)
+    })
+
+
 # ─── Alerts and History ────────────────────────
 
 @inventory_bp.route('/alerts', methods=['GET'])

pos/templates/inventory.html

@@ -238,25 +238,25 @@
       <!-- Tabs Row -->
       <div class="tabs-row" role="tablist" aria-label="Módulos de Inventario">
         <button class="tab-btn is-active" role="tab" aria-selected="true"  aria-controls="panel-stock"      onclick="switchTab('stock')">
-          Stock Actual <span class="tab-btn__badge">4,817</span>
+          Stock Actual <span class="tab-btn__badge" id="badge-stock">0</span>
         </button>
         <button class="tab-btn" role="tab" aria-selected="false" aria-controls="panel-entradas"   onclick="switchTab('entradas')">
-          Entradas <span class="tab-btn__badge">14</span>
+          Entradas <span class="tab-btn__badge" id="badge-entradas">0</span>
         </button>
         <button class="tab-btn" role="tab" aria-selected="false" aria-controls="panel-salidas"    onclick="switchTab('salidas')">
-          Salidas
+          Salidas <span class="tab-btn__badge" id="badge-salidas">0</span>
         </button>
         <button class="tab-btn" role="tab" aria-selected="false" aria-controls="panel-traspasos"  onclick="switchTab('traspasos')">
-          Traspasos <span class="tab-btn__badge">3</span>
+          Traspasos <span class="tab-btn__badge" id="badge-traspasos">0</span>
         </button>
         <button class="tab-btn" role="tab" aria-selected="false" aria-controls="panel-ajustes"    onclick="switchTab('ajustes')">
-          Ajustes
+          Ajustes <span class="tab-btn__badge" id="badge-ajustes">0</span>
         </button>
         <button class="tab-btn" role="tab" aria-selected="false" aria-controls="panel-conteos"    onclick="switchTab('conteos')">
-          Conteos
+          Conteos <span class="tab-btn__badge" id="badge-conteos">0</span>
         </button>
         <button class="tab-btn" role="tab" aria-selected="false" aria-controls="panel-alertas"    onclick="switchTab('alertas')">
-          Alertas <span class="tab-btn__badge tab-btn__badge--alert">23</span>
+          Alertas <span class="tab-btn__badge tab-btn__badge--alert" id="badge-alertas">0</span>
         </button>
       </div>
 
@@ -821,5 +821,34 @@
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
   <script src="/pos/static/js/pwa-install.js" defer></script>
   <script src="/pos/static/js/chat.js" defer></script>
+  <script>
+    // Load inventory stats for tab badges
+    (async function loadInventoryStats() {
+      try {
+        const token = localStorage.getItem('access_token');
+        if (!token) return;
+        const res = await fetch('/pos/api/inventory/stats', {
+          headers: { 'Authorization': 'Bearer ' + token }
+        });
+        if (!res.ok) return;
+        const data = await res.json();
+        const map = {
+          'badge-stock': data.stock,
+          'badge-entradas': data.entradas,
+          'badge-salidas': data.salidas,
+          'badge-traspasos': data.traspasos,
+          'badge-ajustes': data.ajustes,
+          'badge-conteos': data.conteos,
+          'badge-alertas': data.alertas
+        };
+        for (const [id, value] of Object.entries(map)) {
+          const el = document.getElementById(id);
+          if (el) el.textContent = value || 0;
+        }
+      } catch (e) {
+        console.error('Failed to load inventory stats:', e);
+      }
+    })();
+  </script>
 </body>
 </html>