Use index-based unique identifiers for download client selection to prevent cross-selection

public/app.js

@@ -386,7 +386,9 @@ function renderDownloads() {
   // Filter downloads by selected clients
   let filteredDownloads = downloads;
   if (selectedDownloadClients.length > 0) {
-    filteredDownloads = downloads.filter(d => selectedDownloadClients.includes(d.instanceId));
+    // Map indices to instanceIds
+    const selectedInstanceIds = selectedDownloadClients.map(idx => downloadClients[idx]?.id).filter(Boolean);
+    filteredDownloads = downloads.filter(d => selectedInstanceIds.includes(d.instanceId));
   }
 
   // Sort downloads by client order (matching the order in downloadClients)
@@ -1109,7 +1111,7 @@ function initDownloadClientFilter() {
   if (selectAllBtn) {
     selectAllBtn.addEventListener('click', (e) => {
       e.stopPropagation();
-      selectedDownloadClients = downloadClients.map(c => c.id);
+      selectedDownloadClients = downloadClients.map((_, idx) => idx);
       localStorage.setItem('sofarr-download-clients', JSON.stringify(selectedDownloadClients));
       updateDownloadClientFilter();
       renderDownloads();
@@ -1139,6 +1141,19 @@ function updateDownloadClientFilter() {
     return;
   }
 
+  // Migrate old client.id values to indices
+  if (selectedDownloadClients.length > 0 && typeof selectedDownloadClients[0] === 'string') {
+    const migratedIndices = [];
+    selectedDownloadClients.forEach(clientId => {
+      const index = downloadClients.findIndex(c => c.id === clientId);
+      if (index !== -1) {
+        migratedIndices.push(index);
+      }
+    });
+    selectedDownloadClients = migratedIndices;
+    localStorage.setItem('sofarr-download-clients', JSON.stringify(selectedDownloadClients));
+  }
+
   // Add checkboxes for each download client
   downloadClients.forEach((client, index) => {
     const option = document.createElement('div');
@@ -1148,13 +1163,13 @@ function updateDownloadClientFilter() {
     const checkbox = document.createElement('input');
     checkbox.type = 'checkbox';
     checkbox.className = 'download-client-checkbox';
-    checkbox.value = client.id;
+    checkbox.value = index; // Use index as unique identifier
-    checkbox.checked = selectedDownloadClients.includes(client.id);
+    checkbox.checked = selectedDownloadClients.includes(index);
     checkbox.id = checkboxId;
 
     // Toggle selection when checkbox changes
     checkbox.addEventListener('change', (e) => {
-      toggleClientSelection(client.id, e.target.checked);
+      toggleClientSelection(index, e.target.checked);
     });
 
     const label = document.createElement('label');
@@ -1197,7 +1212,7 @@ function updateSelectedCountDisplay() {
   if (selectedDownloadClients.length === 0) {
     selectedText.textContent = 'All clients';
   } else if (selectedDownloadClients.length === 1) {
-    const client = downloadClients.find(c => c.id === selectedDownloadClients[0]);
+    const client = downloadClients[selectedDownloadClients[0]];
     selectedText.textContent = client ? client.name : '1 selected';
   } else {
     selectedText.textContent = `${selectedDownloadClients.length} selected`;