implement fe with backend

docs/SALES_MODULE_PLAN.md

@@ -229,13 +229,15 @@ When an invoice or slip is posted:
 - `POST /api/v1/sales-slips`
 - `POST /api/v1/sales-slips/{id}/post`
 - `POST /api/v1/sales-slips/{id}/cancel`
-- `GET /api/v1/sales-reports/daily-summary`
-- `GET /api/v1/sales-reports/item-wise`
-- `GET /api/v1/sales-reports/customer-wise`
-- `GET /api/v1/sales-reports/warehouse-wise`
-- `GET /api/v1/sales-reports/discount-summary`
-- `GET /api/v1/sales-reports/free-issue-summary`
-- `GET /api/v1/sales-reports/margin-summary`
+- `GET /api/v1/free-issues`
+- `GET /api/v1/free-issues/{id}`
+- `POST /api/v1/free-issues`
+- `PUT /api/v1/free-issues/{id}`
+- `POST /api/v1/free-issues/{id}/post`
+- `POST /api/v1/free-issues/{id}/cancel`
+- `GET /api/v1/reports/sales`
+- `GET /api/v1/reports/sales/{reportId}`
+- `POST /api/v1/reports/sales/query`
 
 ### Phase 1 Folder / Module Plan
 - `Domain/Entities`
@@ -264,7 +266,7 @@ When an invoice or slip is posted:
 4. Pricing resolver
 5. Discount computation
 6. Free issue handling
-7. Stock posting and ledger integration
+7. Stock posting
 8. Basic sales reports
 9. Controllers and swagger wiring