Feat(connectivity): add Perplexity to the AI list

Add Perplexity to the AI import list, plus its favicon.

Hugging Face is already on the list. The earlier Replicate change was closed unmerged, so this uses a different site.

Related to #399

frontend/data/connectivity-import-lists.js

@@ -195,6 +195,7 @@ export const IMPORT_LISTS = [
             { id: 'kimi', name: 'Kimi', url: 'https://www.kimi.com/favicon.ico' },
             { id: 'poe', name: 'Poe', url: 'https://poe.com/favicon.ico' },
             { id: 'characterai', name: 'Character.ai', url: 'https://character.ai/favicon.ico' },
+            { id: 'perplexity', name: 'Perplexity', url: 'https://www.perplexity.ai/favicon.ico' },
         ],
     },
     {