fix(front-end): quantity changes and normalization

frontend/src/app/features/calculator/calculator-page.component.ts

@@ -226,9 +226,10 @@ export class CalculatorPageComponent implements OnInit {
     this.step.set('quote');
   }
 
-  onItemChange(event: {id?: string, fileName: string, quantity: number}) {
+  onItemChange(event: {id?: string, index: number, fileName: string, quantity: number}) {
       // 1. Update local form for consistency (UI feedback)
       if (this.uploadForm) {
+          this.uploadForm.updateItemQuantityByIndex(event.index, event.quantity);
           this.uploadForm.updateItemQuantityByName(event.fileName, event.quantity);
       }
       

frontend/src/app/features/calculator/components/quote-result/quote-result.component.ts

@@ -22,7 +22,7 @@ export class QuoteResultComponent implements OnDestroy {
   result = input.required<QuoteResult>();
   consult = output<void>();
   proceed = output<void>();
-  itemChange = output<{id?: string, fileName: string, quantity: number}>();
+  itemChange = output<{id?: string, index: number, fileName: string, quantity: number}>();
 
   // Local mutable state for items to handle quantity changes
   items = signal<QuoteItem[]>([]);
@@ -83,6 +83,7 @@ export class QuoteResultComponent implements OnDestroy {
 
       this.itemChange.emit({
           id: item.id,
+          index,
           fileName: item.fileName,
           quantity: normalizedQty
       });

frontend/src/app/features/calculator/components/upload-form/upload-form.component.ts

@@ -199,11 +199,28 @@ export class UploadFormComponent implements OnInit {
       }
   }
 
-  updateItemQuantityByName(fileName: string, quantity: number) {
+  updateItemQuantityByIndex(index: number, quantity: number) {
+      if (!Number.isInteger(index) || index < 0) return;
+      const normalizedQty = this.normalizeQuantity(quantity);
+
       this.items.update(current => {
+          if (index >= current.length) return current;
+          const updated = [...current];
+          updated[index] = { ...updated[index], quantity: normalizedQty };
+          return updated;
+      });
+  }
+
+  updateItemQuantityByName(fileName: string, quantity: number) {
+      const targetName = this.normalizeFileName(fileName);
+      const normalizedQty = this.normalizeQuantity(quantity);
+
+      this.items.update(current => {
+          let matched = false;
           return current.map(item => {
-              if (item.file.name === fileName) {
-                  return { ...item, quantity };
+              if (!matched && this.normalizeFileName(item.file.name) === targetName) {
+                  matched = true;
+                  return { ...item, quantity: normalizedQty };
               }
               return item;
           });
@@ -239,14 +256,9 @@ export class UploadFormComponent implements OnInit {
 
   updateItemQuantity(index: number, event: Event) {
       const input = event.target as HTMLInputElement;
-      let val = parseInt(input.value, 10);
-      if (isNaN(val) || val < 1) val = 1;
-
-      this.items.update(current => {
-          const updated = [...current];
-          updated[index] = { ...updated[index], quantity: val };
-          return updated;
-      });
+      const parsed = parseInt(input.value, 10);
+      const quantity = Number.isFinite(parsed) ? parsed : 1;
+      this.updateItemQuantityByIndex(index, quantity);
   }
 
   updateItemColor(index: number, newSelection: string | { colorName: string; filamentVariantId?: number }) {
@@ -387,4 +399,19 @@ export class UploadFormComponent implements OnInit {
       this.form.get('itemsTouched')?.setValue(true);
     }
   }
+
+  private normalizeQuantity(quantity: number): number {
+      if (!Number.isFinite(quantity) || quantity < 1) {
+          return 1;
+      }
+      return Math.floor(quantity);
+  }
+
+  private normalizeFileName(fileName: string): string {
+      return (fileName || '')
+          .split(/[\\/]/)
+          .pop()
+          ?.trim()
+          .toLowerCase() ?? '';
+  }
 }