feat: add problem detection framework for common problems (#2412)

Introduces a ProblemManager that detects and surfaces actionable issues
(stale config, legacy frigate-hass-card resources, slow/failed streams)
via status bar indicators and notification popups with fix actions.

src/config/schema/common/link.ts

@@ -0,0 +1,7 @@
+import { z } from 'zod';
+
+export const linkSchema = z.object({
+  url: z.string(),
+  title: z.string(),
+});
+export type Link = z.infer<typeof linkSchema>;