feat: add comprehensive loading feedback (#18)

frontend/src/app/components/apartment-form/apartment-form.spec.ts

@@ -50,4 +50,17 @@ describe('ApartmentForm', () => {
       description: 'Cinquième étage',
     });
   });
+
+  it('disables the whole form and preserves a save error while pending', () => {
+    const fixture = TestBed.createComponent(ApartmentForm);
+    fixture.componentRef.setInput('saving', true);
+    fixture.componentRef.setInput('saveError', 'Impossible d’enregistrer cet appartement.');
+    fixture.detectChanges();
+
+    expect(fixture.nativeElement.querySelector('fieldset').disabled).toBe(true);
+    expect(fixture.nativeElement.textContent).toContain('Enregistrement…');
+    expect(fixture.nativeElement.textContent).toContain(
+      'Impossible d’enregistrer cet appartement.',
+    );
+  });
 });