Add Telegram bot reply-keyboard menus and persistent screenshot settings

[HorGonAI]

Motivation

• Restore/provide reply-keyboard (ButtonKeyboard) UI in the Telegram bot so users can navigate menus: main (Скриншот, Настройки), settings → Качество, screenshot submenu → Разрешение, Качество, Сжатие, with Назад navigation and inputs for quality/resolution.
• Ensure screenshot sending respects compression setting (send as photo or document) and that user settings persist across restarts by saving them back to the config file.

Description

• Added menu state machine types MenuState and per-chat ChatState, and a chat_states map to track each chat's menu state (file: src/main.cpp).
• Implemented keyboard JSON helpers escapeJsonString and buildKeyboardJson and reply-send helper sendMessageWithReplyMarkup, plus convenience menu display functions showMainMenu, showSettingsMenu, showQualityMenu, showScreenshotMenu, showResolutionMenu, showQualityInputPrompt (file: src/main.cpp).
• Added persistent config save helpers saveConfig and joinChatIds, and integrated saving of screenshot settings when changed (file: src/main.cpp).
• Added sendDocument and updated screenshot delivery logic to send as document when compression is disabled; select sendPhoto when compression is enabled (file: src/main.cpp).
• Hooked menu navigation and input handling into the main update loop: resolution selection (720,1080,1440), numeric quality input validation (10–100), compression toggle (Сжатие: вкл/выкл), and Назад handling to return to previous menus; settings updates persist to the config file (file: src/main.cpp).

Testing

• No automated tests were executed for this change.

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Codex Task