feat(profile): account-deletion flow + terminal deleted screen

Profile gains a Delete-account control (durable accounts) opening a step-up dialog: a
mailed code for an email account, or the typed DELETE phrase for a platform-only one.
On success the app swaps to a terminal AccountDeleted screen ('Учётная запись удалена')
with a Close that closes the host Mini App (telegramClose / vkClose; web = no close).
Wires deleteRequest/deleteConfirm through client/transport/mock/codec; ru/en i18n;
codec wire test + Chromium/WebKit e2e.

ui/src/lib/mock/client.ts

@@ -687,6 +687,10 @@ export class MockGateway implements GatewayClient {
     this.profile.email = email;
     return { ...emptyLinked(), status: 'changed' };
   }
+  async deleteRequest(): Promise<{ method: 'email' | 'phrase' }> {
+    return { method: this.profile.email ? 'email' : 'phrase' };
+  }
+  async deleteConfirm(_code: string, _phrase: string): Promise<void> {}
   async statsGet(): Promise<Stats> {
     return { ...this.stats };
   }