fix(bot): promo auto-delete + neutralize fake install/change stubs

Two user-reported bugs:

1. Promo spam: daily promo message from /start and the Promo menu
   button stayed in chat forever. Now they auto-delete after 30s.
   - new helper _delete_message_after()
   - cmd_start schedules deletion of the daily promo
   - cb_menu_promo sends promo as a SEPARATE ephemeral message
     (instead of editing the main menu in place), so the menu stays
     intact and only the promo self-destructs in 30s.

2. CRITICAL: 'install/change template from bot' was a stub that
   silently corrupted /opt/gotelegram/config.json. cb_lite_domain
   and cb_pro_confirm wrote a fake minimal config ({mode,template,
   port,installed_at}) without secret/domain/mask_host, and showed
   '[OK] installed!' — while never invoking install.sh, never
   downloading the template, never touching nginx. Proxy link
   generation then broke because secret was gone.
   User symptom: 'устанавливал другой шаблон через бота и всё
   повисло'.

   Fix: both callbacks now refuse cleanly and route the user to the
   CLI ('gotelegram' command → menu 1 → 1 or 7). Configuration is
   NOT touched. Full non-interactive install/change from the bot is
   left as future work.

Tested live on VPS:
- bot.py syntax OK (ast.parse on VPS)
- gotelegram-bot restarted, active
- corrupted config.json on VPS rebuilt from telemt TOML ground
  truth (mode=lite, secret, port, mask_host=google.com)

gotelegram-bot/bot.py

@@ -288,6 +288,17 @@ async def safe_edit_message(query, text: str, reply_markup=None, parse_mode=None
         raise  # Re-raise unexpected BadRequest
 
 
+async def _delete_message_after(message, delay: int = 30) -> None:
+    """Delete a Telegram message after `delay` seconds. Errors are swallowed
+    (message may already be deleted by the user). Used for ephemeral content
+    like promo blocks that should auto-cleanup."""
+    try:
+        await asyncio.sleep(delay)
+        await message.delete()
+    except Exception as e:
+        logger.debug(f"_delete_message_after: {e}")
+
+
 async def check_service_status(service: str) -> bool:
     """Check if systemd service is running."""
     code, _, _ = await sh("systemctl", "is-active", service)
@@ -465,12 +476,13 @@ async def cmd_start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
         welcome, reply_markup=get_main_menu(user_id), parse_mode="HTML"
     )
 
-    # Промо раз в сутки
+    # Промо раз в сутки — сообщение само удаляется через 30 секунд
     if should_show_promo_bot():
         mark_promo_shown_bot()
-        await update.message.reply_text(
-            get_promo_text(), parse_mode="HTML"
+        promo_msg = await update.message.reply_text(
+            get_promo_text(), parse_mode="HTML", disable_web_page_preview=True
         )
+        asyncio.create_task(_delete_message_after(promo_msg, 30))
 
 
 async def cmd_help(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
@@ -796,7 +808,17 @@ async def cb_install_mode_lite(update: Update, context: ContextTypes.DEFAULT_TYP
 
 
 async def cb_lite_domain(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
-    """Lite domain selection callback."""
+    """Lite domain selection callback — safe stub.
+
+    Historic bug (v2.4.1): this callback used to overwrite
+    /opt/gotelegram/config.json with a minimal fake config (no secret, no
+    mask_host, no engine), silently corrupting the live proxy and showing a
+    fake "✅ Lite mode installed!" — while never actually invoking install.sh.
+
+    Installing/changing modes non-interactively from the bot is not yet wired
+    up. Until it is, refuse cleanly and route the user to the CLI instead of
+    damaging the working configuration.
+    """
     query = update.callback_query
     data = query.data
     try:
@@ -807,36 +829,19 @@ async def cb_lite_domain(update: Update, context: ContextTypes.DEFAULT_TYPE) ->
         return
 
     await query.answer()
-    await safe_edit_message(query,f"⏳ Installing with domain: {domain}...")
 
-    # Simulate installation (in real scenario, call install script)
-    config = {
-        "mode": "lite",
-        "domain": domain,
-        "port": 443,
-        "installed_at": datetime.now().isoformat(),
-    }
-
-    if save_json(GOTELEGRAM_CONFIG, config):
     text = (
-            f"✅ <b>Lite mode installed!</b>\n\n"
-            f"<b>Domain:</b> {domain}\n"
-            f"<b>Mode:</b> Lite\n\n"
-            f"Service starting... Check status in 10 seconds."
+        "<b>⚠️ Установка из бота пока не поддерживается</b>\n\n"
+        f"Выбранный домен: <code>{html.escape(domain)}</code>\n\n"
+        "Чтобы установить или переключить режим Lite, запустите на сервере:\n"
+        "<code>gotelegram</code>\n\n"
+        "Затем: <b>1) Прокси → 1) Установить/Обновить → Lite</b>.\n\n"
+        "Существующая конфигурация <b>не была изменена</b>."
     )
     keyboard = InlineKeyboardMarkup(
         [[InlineKeyboardButton(_t(_uid(update), "btn_back"), callback_data="menu_main")]]
     )
-        await safe_edit_message(query,
-            text, reply_markup=keyboard, parse_mode="HTML"
-        )
-    else:
-        await safe_edit_message(query,
-            "❌ Failed to save configuration",
-            reply_markup=InlineKeyboardMarkup(
-                [[InlineKeyboardButton("« Back", callback_data="menu_install")]]
-            ),
-        )
+    await safe_edit_message(query, text, reply_markup=keyboard, parse_mode="HTML")
 
 
 async def cb_install_mode_pro(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
@@ -1106,41 +1111,39 @@ async def cb_pro_template(update: Update, context: ContextTypes.DEFAULT_TYPE) ->
 
 
 async def cb_pro_confirm(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
-    """Confirm and install pro template."""
+    """Confirm Pro template selection — safe stub.
+
+    Historic bug (v2.4.1): this callback used to overwrite
+    /opt/gotelegram/config.json with a fake {"mode":"pro","template":...,
+    "port":443} blob — no secret, no domain, no mask_host — silently
+    corrupting the live proxy so link generation and status broke. At the
+    same time the user saw "✅ Pro mode installed!" although install.sh was
+    never invoked, no template was actually downloaded, nginx was not
+    reconfigured and certbot was not touched.
+
+    Non-interactive Pro install/change from the bot is not yet implemented.
+    Until it is, refuse cleanly and route the user to the CLI instead of
+    damaging the working configuration.
+    """
     query = update.callback_query
     data = query.data
     tpl_id = data.removeprefix("pro_confirm_")
 
     await query.answer()
-    await safe_edit_message(query,"⏳ Installing template...")
 
-    config = {
-        "mode": "pro",
-        "template": tpl_id,
-        "port": 443,
-        "installed_at": datetime.now().isoformat(),
-    }
-
-    if save_json(GOTELEGRAM_CONFIG, config):
     text = (
-            f"✅ <b>Pro mode installed!</b>\n\n"
-            f"<b>Template:</b> {html.escape(tpl_id)}\n"
-            f"<b>Mode:</b> Pro\n\n"
-            f"Service starting... Check status in 10 seconds."
+        "<b>⚠️ Установка шаблона из бота пока не поддерживается</b>\n\n"
+        f"Выбранный шаблон: <code>{html.escape(tpl_id)}</code>\n\n"
+        "Чтобы установить или сменить шаблон, запустите на сервере:\n"
+        "<code>gotelegram</code>\n\n"
+        "Затем: <b>1) Прокси → 1) Установить/Обновить → Pro</b> "
+        "(или <b>7) Сменить режим/шаблон</b> для смены текущего).\n\n"
+        "Существующая конфигурация <b>не была изменена</b>."
     )
     keyboard = InlineKeyboardMarkup(
         [[InlineKeyboardButton(_t(_uid(update), "btn_back"), callback_data="menu_main")]]
     )
-        await safe_edit_message(query,
-            text, reply_markup=keyboard, parse_mode="HTML"
-        )
-    else:
-        await safe_edit_message(query,
-            "❌ Failed to save configuration",
-            reply_markup=InlineKeyboardMarkup(
-                [[InlineKeyboardButton("« Back", callback_data="menu_install")]]
-            ),
-        )
+    await safe_edit_message(query, text, reply_markup=keyboard, parse_mode="HTML")
 
 
 # ============================================================================
@@ -1799,14 +1802,16 @@ def mark_promo_shown_bot() -> None:
 
 
 async def cb_menu_promo(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
-    """Promo information — always shown from menu."""
+    """Promo information — shown as a separate ephemeral message that
+    auto-deletes after 30s so it does not clutter the chat. The main menu
+    message stays intact (we don't edit it in place)."""
     query = update.callback_query
     await query.answer()
 
-    keyboard = InlineKeyboardMarkup(
-        [[InlineKeyboardButton(_t(_uid(update), "btn_back"), callback_data="menu_main")]]
+    promo_msg = await query.message.reply_text(
+        get_promo_text(), parse_mode="HTML", disable_web_page_preview=True
     )
-    await safe_edit_message(query, get_promo_text(), reply_markup=keyboard, parse_mode="HTML")
+    asyncio.create_task(_delete_message_after(promo_msg, 30))
 
 
 async def cb_menu_credits(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None: