feat(accounts): add precise service filtering

Add an explicit service selector to the account creation dialog while keeping the text field focused on access types such as API and web login. Preserve the result area dimensions during filtering and allow Enter to choose the first visible account type. Cover filtering, keyboard selection, translations, and stable list geometry with focused regression tests.

src/renderer/account-ui.ts

@@ -16,6 +16,27 @@ export function matchesAccountModeFilter(option: AccountModeOption, filter: Acco
   return option.modeLabel.startsWith("Web");
 }
 
+export function filterAccountDialogOptions<T extends {
+  serviceLabel: string;
+  title: string;
+  modeLabel: string;
+  pickerDescription: string;
+}>(options: readonly T[], query: string, serviceFilter: string): T[] {
+  const normalizedQuery = query.trim().toLocaleLowerCase("de-DE");
+  return options.filter((option) => {
+    if (serviceFilter !== "all" && option.serviceLabel !== serviceFilter) {
+      return false;
+    }
+    if (!normalizedQuery) {
+      return true;
+    }
+    return [option.title, option.modeLabel, option.pickerDescription]
+      .join(" ")
+      .toLocaleLowerCase("de-DE")
+      .includes(normalizedQuery);
+  });
+}
+
 export function buildConfiguredProviderOrder(
   currentOrder: readonly DebridProvider[],
   configuredProviders: readonly DebridProvider[]