Fix business tenant binding and update password on cross-site signup.

Resolve the active business from the host domain so multi-business staff no longer load another tenant’s CMS data, and replace the Meshkee password when linking an existing account to a new site.

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/dashboard-core/src/types/auth.ts

@@ -51,6 +51,8 @@ export interface MeResponse {
 
 export interface RegisterResponse extends LoginResponse {
   smsEnabled?: boolean
+  /** True when an existing Meshkee account was linked and its password was replaced. */
+  passwordUpdated?: boolean
   registeredBusiness?: { id: string; name: string; slug: string }
 }