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/migrations/v4.16_remission_courier.sql

@@ -0,0 +1,18 @@
+-- v4.16: Add courier assignment to counter remission notes.
+
+ALTER TABLE sales
+    ADD COLUMN IF NOT EXISTS courier_id INTEGER;
+
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT 1 FROM pg_constraint
+        WHERE conname = 'sales_courier_id_fkey'
+    ) THEN
+        ALTER TABLE sales
+            ADD CONSTRAINT sales_courier_id_fkey
+            FOREIGN KEY (courier_id) REFERENCES couriers(id);
+    END IF;
+END $$;
+
+CREATE INDEX IF NOT EXISTS idx_sales_courier_id ON sales(courier_id);