add subscriptions; change persistence file format to JSON (closes #901, #76, #113, #170, #242, #444, #503, #555, #566)

ui/src/app/interfaces/index.ts

@@ -6,4 +6,4 @@ export * from './download';
 export * from './checkable';
 export * from './format';
 export * from './formats';
-
+export * from './subscription';

ui/src/app/interfaces/subscription.ts

@@ -0,0 +1,15 @@
+export interface SubscriptionRow {
+  id: string;
+  name: string;
+  url: string;
+  enabled: boolean;
+  check_interval_minutes: number;
+  download_type: string;
+  codec: string;
+  format: string;
+  quality: string;
+  folder: string;
+  last_checked: number | null;
+  seen_count: number;
+  error: string | null;
+}