Fix: mobile TMA operator layout, Back and Cancel navigation

[EpicStarAi]

Problem

On Telegram mobile, the /tma/profile operator bottom sheet had overlapping header/context/history content. The decorative drag handle occupied an unintended CSS Grid row, so the panel rendered five content rows against a four-row grid. The operator also lacked a distinct internal Back action and consistent Cancel wording.

Fix

• preserve the required four-row layout: header / context / history / footer
• make gradient and drag handle absolute so they no longer consume grid rows
• add an explicit Back button inside the AI Operator
• add profile Back behavior with Telegram WebApp close fallback
• integrate Telegram WebApp BackButton:
  • expanded → compact
  • compact → close operator
• compact mobile height set to 58dvh with minimum and safe viewport constraints
• independent history scrolling with min-h-0, overflow-y-auto, and overscroll-contain
• fixed context bar and footer separation
• replace Deny / Allow labels with Отмена / Разрешить
• preserve safety behavior and Telegram mutation guards

QA

• Android Telegram Mini App: no overlap between header, Telegram context, history, approval card, and input
• compact operator keeps profile visible
• expanded operator uses 100dvh
• internal Back: expanded → compact → closed
• Telegram Back Button follows the same order
• Cancel produces cancelled UI and TELEGRAM_MUTATION=false
• input remains visible above safe area
• desktop floating enhancer remains unaffected

Safety

UI/layout-only change. No Telegram send, executor, or approval bypass is introduced.