feat: add product to opportunity route, local product sequencing

- Add POST /v1/sales/opportunities/:identifier/products with field-level permission gating
- Add CWForecastItemCreate type for forecast item creation
- Store product display order locally (productSequence Int[] on Opportunity)
- Rewrite resequenceProducts to be local-only (no CW PUT, stable IDs)
- Remove reorderProducts CW util (PUT regenerated IDs & broke procurement)
- Update fetchProducts to apply local ordering with CW sequenceNumber fallback
- Add productSequence to OpportunityController.toJson()
- Update API_ROUTES.md, PERMISSIONS.md, PermissionNodes.ts

generated/prisma/internal/prismaNamespace.ts

@@ -1334,6 +1334,7 @@ export const OpportunityScalarFieldEnum = {
   closedByName: 'closedByName',
   closedByCwId: 'closedByCwId',
   companyId: 'companyId',
+  productSequence: 'productSequence',
   cwLastUpdated: 'cwLastUpdated',
   createdAt: 'createdAt',
   updatedAt: 'updatedAt'

generated/prisma/internal/prismaNamespaceBrowser.ts

@@ -221,6 +221,7 @@ export const OpportunityScalarFieldEnum = {
   closedByName: 'closedByName',
   closedByCwId: 'closedByCwId',
   companyId: 'companyId',
+  productSequence: 'productSequence',
   cwLastUpdated: 'cwLastUpdated',
   createdAt: 'createdAt',
   updatedAt: 'updatedAt'