feat(config): allow admin/owner to delete branches

- Added DELETE /pos/api/config/branches/<id> that soft-deletes the branch (is_active=false).

- Restricted to owner/admin; main branch cannot be deleted.

- Added 'Eliminar' button in the branches grid for admin/owner.

pos/blueprints/config_bp.py

@@ -150,6 +150,33 @@ def update_branch(branch_id):
     return jsonify({'ok': True, 'message': 'Branch updated'})
 
 
+@config_bp.route('/branches/<int:branch_id>', methods=['DELETE'])
+@require_auth('config.edit')
+def delete_branch(branch_id):
+    """Soft-delete a branch. Only owner/admin can delete; main branch cannot be deleted."""
+    if g.employee_role not in ('owner', 'admin'):
+        return jsonify({'error': 'Solo administradores pueden eliminar sucursales'}), 403
+
+    conn = get_tenant_conn(g.tenant_id)
+    cur = conn.cursor()
+
+    cur.execute("SELECT is_main FROM branches WHERE id = %s", (branch_id,))
+    row = cur.fetchone()
+    if not row:
+        cur.close(); conn.close()
+        return jsonify({'error': 'Branch not found'}), 404
+
+    if row[0]:
+        cur.close(); conn.close()
+        return jsonify({'error': 'No se puede eliminar la sucursal principal'}), 403
+
+    cur.execute("UPDATE branches SET is_active = false WHERE id = %s", (branch_id,))
+    conn.commit()
+    cur.close()
+    conn.close()
+    return jsonify({'ok': True, 'message': 'Sucursal eliminada'})
+
+
 @config_bp.route('/employees', methods=['GET'])
 @require_auth()
 def list_employees():