feat: add unit mapping functionality

- Added new API path for unit mappings in `api_paths.dart`.
- Implemented `upsertUnitMapping` method in `ImportRepository` to handle unit mapping creation.
- Updated `ReceiptImportTab` to learn and save unit mappings during receipt import.
- Created DTO for unit mapping with validation in `create-unit-mapping.dto.ts`.
- Added SQL migration for `UnitMapping` table creation with necessary constraints.

backend/dist/pantry/dto/create-pantry-item.dto.d.ts

@@ -1,3 +1,4 @@
 export declare class CreatePantryItemDto {
     productId: number;
+    location?: string;
 }

backend/dist/pantry/dto/create-pantry-item.dto.js

@@ -19,4 +19,10 @@ __decorate([
     (0, class_validator_1.IsPositive)(),
     __metadata("design:type", Number)
 ], CreatePantryItemDto.prototype, "productId", void 0);
+__decorate([
+    (0, class_validator_1.IsOptional)(),
+    (0, class_validator_1.IsString)(),
+    (0, class_validator_1.MaxLength)(50),
+    __metadata("design:type", String)
+], CreatePantryItemDto.prototype, "location", void 0);
 //# sourceMappingURL=create-pantry-item.dto.js.map

backend/dist/pantry/dto/create-pantry-item.dto.js.map

@@ -1 +1 @@
-{"version":3,"file":"create-pantry-item.dto.js","sourceRoot":"","sources":["../../../src/pantry/dto/create-pantry-item.dto.ts"],"names":[],"mappings":";;;;;;;;;;;;AAAA,qDAAoD;AAEpD,MAAa,mBAAmB;CAI/B;AAJD,kDAIC;AADC;IAFC,IAAA,uBAAK,GAAE;IACP,IAAA,4BAAU,GAAE;;sDACK"}
+{"version":3,"file":"create-pantry-item.dto.js","sourceRoot":"","sources":["../../../src/pantry/dto/create-pantry-item.dto.ts"],"names":[],"mappings":";;;;;;;;;;;;AAAA,qDAAqF;AAErF,MAAa,mBAAmB;CAS/B;AATD,kDASC;AANC;IAFC,IAAA,uBAAK,GAAE;IACP,IAAA,4BAAU,GAAE;;sDACK;AAKlB;IAHC,IAAA,4BAAU,GAAE;IACZ,IAAA,0BAAQ,GAAE;IACV,IAAA,2BAAS,EAAC,EAAE,CAAC;;qDACI"}