Smart Sell: Make it clear no Buy order is being placed

Smart Sell currently uses buy-order wording for coins the user already owns, and that's confusing. Please change the Smart Sell UI as follows:

Chart: “Buy” → “Bought”
Confirmation title: “Confirm orders” → “Confirm Smart Sell”
“1 Entry order(s)” → “Existing Holding”
“Buy BTC” → “Existing BTC”
“Limit price” → “Recorded Buy Price”
“Spend USDT” → “Recorded Cost”

Keep the actual exit wording “Sell BTC” unchanged.

Also add this message prominently in the confirmation window:
“No buy order will be placed. Smart Sell only manages coins you already own.”