Improve 404 navigation and styling

src-ui/src/app/components/document-detail/document-detail.component.spec.ts

@@ -355,14 +355,14 @@ describe('DocumentDetailComponent', () => {
       .mockReturnValueOnce(throwError(() => new Error('unable to discard')))
     component.discard()
     fixture.detectChanges()
-    expect(navigateSpy).toHaveBeenCalledWith(['404'])
+    expect(navigateSpy).toHaveBeenCalledWith(['404'], { replaceUrl: true })
   })
 
   it('should 404 on invalid id', () => {
     jest.spyOn(documentService, 'get').mockReturnValueOnce(of(null))
     const navigateSpy = jest.spyOn(router, 'navigate')
     fixture.detectChanges()
-    expect(navigateSpy).toHaveBeenCalledWith(['404'])
+    expect(navigateSpy).toHaveBeenCalledWith(['404'], { replaceUrl: true })
   })
 
   it('should support save, close and show success toast', () => {

src-ui/src/app/components/document-detail/document-detail.component.ts

@@ -341,7 +341,9 @@ export class DocumentDetailComponent
           this.openDocumentService.setDirty(doc, dirty)
         },
         error: (error) => {
-          this.router.navigate(['404'])
+          this.router.navigate(['404'], {
+            replaceUrl: true,
+          })
         },
       })
 
@@ -513,7 +515,9 @@ export class DocumentDetailComponent
           this.openDocumentService.setDirty(doc, false)
         },
         error: () => {
-          this.router.navigate(['404'])
+          this.router.navigate(['404'], {
+            replaceUrl: true,
+          })
         },
       })
   }