TradingView Text Alert Indicator

I need a Pine Script companion that watches the text my primary script already paints on the chart—simple “Buy” or “Sell” labels that appear just above or below each candle—and fires an alert only after the next bar closes. The logic is straightforward:

• On every bar close, read the label that was drawn on the immediately preceding bar.
• Ignore whatever the active (forming) bar might be showing.
• Treat “Buy”, “buy”, “BUY”, “Sell”, “sell”, or “SELL” as equivalent so the script must be case-insensitive.
• If the label is valid, trigger a TradingView alert whose message is nothing more than that word: either “Buy” or “Sell”. No extra text, no bar details.

Deliverables:
1. Clean, commented Pine Script (v5 preferred) that implements the above.
2. A brief note showing the alert syntax I should paste into the TradingView alert creation dialog.
3. Confirmation that the script behaves correctly on both real-time and historical replays.

If you have built similar text-parsing indicators before, this should be a quick task—please let me know your turnaround time.

Trading View Chart Link:
https://www.tradingview.com/chart/GFQGnqpO/