feat(front-end): calculator improvements

frontend/src/app/features/checkout/checkout.component.html

@@ -245,6 +245,10 @@
                   <span
                     >{{ "CHECKOUT.QTY" | translate }}: {{ item.quantity }}</span
                   >
+                  <span>
+                    {{ "CHECKOUT.MATERIAL" | translate }}:
+                    {{ itemMaterial(item) }}
+                  </span>
                   <span
                     *ngIf="item.colorCode"
                     class="color-dot"
@@ -255,7 +259,7 @@
                   {{ item.printTimeSeconds / 3600 | number: "1.1-1" }}h |
                   {{ item.materialGrams | number: "1.0-0" }}g
                 </div>
-                <div class="item-preview" *ngIf="isStlItem(item)">
+                <div class="item-preview" *ngIf="isCadSession() && isStlItem(item)">
                   <ng-container
                     *ngIf="previewFile(item) as itemPreview; else previewState"
                   >

frontend/src/app/features/checkout/checkout.component.ts

@@ -162,7 +162,11 @@ export class CheckoutComponent implements OnInit {
     this.quoteService.getQuoteSession(this.sessionId).subscribe({
       next: (session) => {
         this.quoteSession.set(session);
-        this.loadStlPreviews(session);
+        if (this.isCadSessionData(session)) {
+          this.loadStlPreviews(session);
+        } else {
+          this.resetPreviewState();
+        }
         console.log('Loaded session:', session);
       },
       error: (err) => {
@@ -173,7 +177,7 @@ export class CheckoutComponent implements OnInit {
   }
 
   isCadSession(): boolean {
-    return this.quoteSession()?.session?.status === 'CAD_ACTIVE';
+    return this.isCadSessionData(this.quoteSession());
   }
 
   cadRequestId(): string | null {
@@ -188,6 +192,12 @@ export class CheckoutComponent implements OnInit {
     return this.quoteSession()?.cadTotalChf ?? 0;
   }
 
+  itemMaterial(item: any): string {
+    return String(
+      item?.materialCode ?? this.quoteSession()?.session?.materialCode ?? '-',
+    );
+  }
+
   isStlItem(item: any): boolean {
     const name = String(item?.originalFilename ?? '').toLowerCase();
     return name.endsWith('.stl');
@@ -241,7 +251,11 @@ export class CheckoutComponent implements OnInit {
   }
 
   private loadStlPreviews(session: any): void {
-    if (!this.sessionId || !Array.isArray(session?.items)) {
+    if (
+      !this.sessionId ||
+      !this.isCadSessionData(session) ||
+      !Array.isArray(session?.items)
+    ) {
       return;
     }
 
@@ -276,6 +290,17 @@ export class CheckoutComponent implements OnInit {
     }
   }
 
+  private isCadSessionData(session: any): boolean {
+    return session?.session?.status === 'CAD_ACTIVE';
+  }
+
+  private resetPreviewState(): void {
+    this.previewFiles.set({});
+    this.previewLoading.set({});
+    this.previewErrors.set({});
+    this.closePreview();
+  }
+
   onSubmit() {
     if (this.checkoutForm.invalid) {
       return;