feat(workshop): allow admin/owner to delete service orders

- Soft-delete service orders via is_deleted flag.

- Added DELETE /pos/api/service-orders/<id> restricted to owner/admin.

- Updated list, detail, summary, status and assignment queries to exclude deleted orders.

- Added 'Eliminar orden' button in the detail modal for administrators.

pos/services/service_order_engine.py

@@ -115,7 +115,7 @@ def get_service_order(conn, so_id):
         LEFT JOIN employees creator ON so.created_by = creator.id
         LEFT JOIN branches b ON so.branch_id = b.id
         LEFT JOIN couriers co ON so.courier_id = co.id
-        WHERE so.id = %s
+        WHERE so.id = %s AND so.is_deleted = false
     """, (so_id,))
     row = cur.fetchone()
     if not row:
@@ -242,7 +242,8 @@ def list_service_orders(conn, status=None, branch_id=None, customer_id=None,
         where_clauses.append("(so.order_number ILIKE %s OR c.name ILIKE %s OR fv.plate ILIKE %s)")
         params.extend([f'%{q}%', f'%{q}%', f'%{q}%'])
 
-    where = " AND ".join(where_clauses) if where_clauses else "true"
+    where_clauses.append("so.is_deleted = false")
+    where = " AND ".join(where_clauses)
 
     cur.execute(f"""
         SELECT count(*) FROM service_orders so
@@ -309,7 +310,7 @@ def list_service_orders(conn, status=None, branch_id=None, customer_id=None,
 def update_status(conn, so_id, new_status, changed_by=None, notes=None):
     """Update service order status with validation."""
     cur = conn.cursor()
-    cur.execute("SELECT status FROM service_orders WHERE id = %s", (so_id,))
+    cur.execute("SELECT status FROM service_orders WHERE id = %s AND is_deleted = false", (so_id,))
     row = cur.fetchone()
     if not row:
         cur.close()
@@ -486,7 +487,7 @@ def get_kanban_summary(conn, branch_id=None):
     cur.execute(f"""
         SELECT status, COUNT(*) as cnt
         FROM service_orders
-        WHERE status != 'cancelled' {branch_filter}
+        WHERE status != 'cancelled' AND is_deleted = false {branch_filter}
         GROUP BY status
     """, params)
 
@@ -499,6 +500,7 @@ def get_kanban_summary(conn, branch_id=None):
         SELECT count(*) FROM service_orders
         WHERE estimated_completion < NOW()
           AND status NOT IN ('ready', 'delivered', 'cancelled')
+          AND is_deleted = false
           {branch_filter}
     """, params)
     overdue = cur.fetchone()[0]
@@ -813,7 +815,7 @@ def convert_to_sale(conn, so_id, sale_data, employee_id=None):
 def assign_mechanic(conn, so_id, employee_id):
     """Assign a mechanic/technician to a service order."""
     cur = conn.cursor()
-    cur.execute("SELECT id FROM service_orders WHERE id = %s", (so_id,))
+    cur.execute("SELECT id FROM service_orders WHERE id = %s AND is_deleted = false", (so_id,))
     if not cur.fetchone():
         cur.close()
         raise ValueError("Service order not found")
@@ -827,6 +829,21 @@ def assign_mechanic(conn, so_id, employee_id):
     return {"employee_id": employee_id}
 
 
+def delete_service_order(conn, so_id):
+    """Soft-delete a service order."""
+    cur = conn.cursor()
+    cur.execute(
+        "UPDATE service_orders SET is_deleted = true WHERE id = %s AND is_deleted = false",
+        (so_id,),
+    )
+    deleted = cur.rowcount
+    conn.commit()
+    cur.close()
+    if deleted == 0:
+        raise ValueError("Service order not found")
+    return {"deleted": True}
+
+
 # ─── Service catalog (reusable labor concepts) ───────────────────────────────