feat: federation batch 1+2 — bug fixes and password enforcement

Batch 1 — Bug fixes:
- Fix stale voice state on remote reconnect (clearVoiceUsersForOrigin)
- Fix logout not cleaning remote servers from store
- Fix reply-to asset normalization for remote messages
- Fix HTTPS hardcoded in autoConnectAll (store full origin, legacy fallback)

Batch 2 — Password enforcement + replication flow:
- Add connectToRemote() with home password verification before remote auth
- Auto-cascade: verify home password → register on remote → login fallback
- Replace Register/Login tabs with single password field in ConnectedInstances
- Add DifferentPasswordError for typed fallback-login UI transition
- Fallback login form shown only when remote has different password

packages/shared/src/types.ts

@@ -14,8 +14,9 @@ export interface User {
 }
 
 export interface ReplicatedInstance {
-  domain: string;
+  origin: string;   // Full URL with protocol, e.g. "https://orbit.ddns.net"
   username: string;
+  domain?: string;  // Legacy field — kept for backward compat with existing data
 }
 
 export type UserStatus = 'online' | 'idle' | 'dnd' | 'offline';