Contacts management

- [ ] View my contacts list
- [ ] Follow my contacts
- [ ] Add to my contacts any fediverse account
- [ ] Invite my contacts to follow me (Invite > Follow)

No files, tests, or entry points are named, so first inspect the Mastopod app structure for contacts-related UI and follow/invite paths. Locate existing components/routes that handle contact lists, then read the related service or API wiring to understand current data flow. Use current behavior as the baseline, and consider the work done only when all four checklist items are implemented end-to-end: view, follow, add, and invite contacts.

由索引模型根據 Issue 內容生成。