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/client.ts

@@ -185,6 +185,11 @@ export interface GatewayClient {
    *  refused without disclosure. */
   changeEmailRequest(email: string): Promise<void>;
   changeEmailConfirm(email: string, code: string): Promise<LinkResult>;
+  /** Start account deletion; the backend mails a code (method 'email') or asks for the
+   *  typed phrase (method 'phrase'). */
+  deleteRequest(): Promise<{ method: 'email' | 'phrase' }>;
+  /** Confirm and perform account deletion with the mailed code or the typed phrase. */
+  deleteConfirm(code: string, phrase: string): Promise<void>;
 
   // --- live stream ---
   subscribe(onEvent: (e: PushEvent) => void, onError?: (err: unknown) => void): Unsubscribe;