make a backup download for browsers that don't get it automatically

src/views/AccountViewView.vue

@@ -162,7 +162,9 @@
     >
       Backup Identifier Seed
     </router-link>
+
     <a
+      v-bind:class="computedStartDownloadLinkClassNames()"
       class="block w-full text-center text-md uppercase bg-slate-500 text-white px-1.5 py-2 rounded-md mb-6"
       @click="exportDatabase()"
     >
@@ -170,7 +172,13 @@
       <br />
       (excluding Identifier Data)
     </a>
-    <a ref="downloadLink" />
+    <a
+      ref="downloadLink"
+      v-bind:class="computedDownloadLinkClassNames()"
+      class="block w-full text-center text-md uppercase bg-slate-500 text-white px-1.5 py-2 rounded-md mb-6"
+    >
+      If no download happened yet, click again here to download now.
+    </a>
 
     <div v-if="activeDid" class="flex py-2">
       <button class="text-center text-md text-blue-500" @click="checkLimits()">
@@ -438,6 +446,7 @@ export default class AccountViewView extends Vue {
   apiServer = "";
   apiServerInput = "";
   derivationPath = "";
+  downloadUrl = ""; // because DuckDuckGo doesn't download on automated call to "click" on the anchor
   givenName = "";
   isRegistered = false;
   numAccounts = 0;
@@ -580,6 +589,12 @@ export default class AccountViewView extends Vue {
     }
   }
 
+  beforeUnmount() {
+    if (this.downloadUrl) {
+      URL.revokeObjectURL(this.downloadUrl);
+    }
+  }
+
   /**
    * Initializes component state with values from the database or defaults.
    * @param {SettingsType} settings - Object containing settings from the database.
@@ -681,13 +696,13 @@ export default class AccountViewView extends Vue {
       const blob = await this.generateDatabaseBlob();
 
       // Create a temporary URL for the blob
-      const url = this.createBlobURL(blob);
+      this.downloadUrl = this.createBlobURL(blob);
 
       // Trigger the download
-      this.downloadDatabaseBackup(url);
+      this.downloadDatabaseBackup(this.downloadUrl);
 
-      // Revoke the temporary URL
-      URL.revokeObjectURL(url);
+      // Revoke the temporary URL -- not yet because of DuckDuckGo download failure
+      //URL.revokeObjectURL(this.downloadUrl);
 
       // Notify the user that the download has started
       this.notifyDownloadStarted();
@@ -724,7 +739,19 @@ export default class AccountViewView extends Vue {
     const downloadAnchor = this.$refs.downloadLink as HTMLAnchorElement;
     downloadAnchor.href = url;
     downloadAnchor.download = `${db.name}-backup.json`;
-    downloadAnchor.click();
+    downloadAnchor.click(); // doesn't work for some browsers, eg. DuckDuckGo
+  }
+
+  public computedStartDownloadLinkClassNames() {
+    return {
+      invisible: this.downloadUrl,
+    };
+  }
+
+  public computedDownloadLinkClassNames() {
+    return {
+      invisible: !this.downloadUrl,
+    };
   }
 
   /**