feat: cashier/counter reports, service-order & remission flows, Rached migration utils

- Add "Mis cortes de caja" report for cashiers/counters with sales detail.
- Cash register history scoped to own cuts for non-admin roles; new /register/<id>/sales endpoint.
- Remove dashboard from cashier menu; add Reports to cashier/counter.
- Service orders: assign mechanic, budget field, invoice flag, counter/cashier can add items/remissions, convert to remission.
- Remission notes module (UI, CSS, courier, counter remissions).
- Customer hard-delete and vehicle/customer linkage in workshop.
- POS: always show search results, compact payment grid, credit validation, tier pricing (5%/10%), ticket with customer/folio.
- Inventory: CSV template with sku_secondary, alias import.
- Rached migration scripts and DB migrations.
- Version-bump cached JS/CSS query strings.

Excludes local Rached session tokens/captures (rached_*.json / rached_*.txt).

pos/templates/invoicing.html

@@ -1063,11 +1063,11 @@
     </div>
   </div>
 
-  <script src="/pos/static/js/i18n.js?v=36" defer></script>
-  <script src="/pos/static/js/app-init.js?v=2" defer></script>
+  <script src="/pos/static/js/i18n.js?v=39" defer></script>
+  <script src="/pos/static/js/app-init.js?v=5" defer></script>
   <script src="/pos/static/js/splash-loader.js?v=33" defer></script>
   <script src="/pos/static/js/pos-utils.js?v=33" defer></script>
-  <script src="/pos/static/js/sidebar.js?v=36" defer></script>
+  <script src="/pos/static/js/sidebar.js?v=44" defer></script>
   <script src="/pos/static/js/invoicing.js?v=33" defer></script>
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>