Suggest carb amount to recover from low glucose on the Add Carb Entry screen #2547

Is your feature request related to a problem? Please describe.
When glucose is low (or predicted to go below the Glucose Safety Limit), there is no guidance on how many carbs to eat to get back into the correction range. The Add Carb Entry screen only accepts an amount, and the Meal Bolus screen then shows "No Bolus Recommended" because glucose is below the safety limit (see attached screenshots: 8 g entered at 23:38, glucose below the 74 mg/dL safety limit).

To find a suitable amount, I currently have to:

1. Type a carb value on the Add Carb Entry screen
2. Tap Continue and look at the predicted glucose curve
3. Go back, change the value, and repeat

The goal is to enter enough carbs to bring the prediction back into range, but not so many that it overshoots into hyperglycemia. This trial-and-error is slow and stressful, especially at night or when already symptomatic, and it is error-prone.

Describe the solution you'd like
When current or predicted glucose is below the Glucose Safety Limit (or below the correction range), show a suggested carb amount on the Add Carb Entry screen, similar to how a recommended bolus is shown on the bolus screen. For example, a "Suggested carbs: X g" row that can be tapped to fill in the quantity.

Possible approach: reuse the existing prediction engine to find the smallest carb amount (using the selected absorption time, carb ratio and ISF, and accounting for active insulin and active carbs) for which the predicted glucose stays above the safety limit and ends up within the correction range. This is conceptually the inverse of the current bolus recommendation.

Some suggestions:

• The value should be a suggestion only, never applied automatically, and clearly labeled as such.
• It could be optional (a setting) and hidden when glucose is not low.
• It could be capped by the existing maximum carb entry guardrail.

Describe alternatives you've considered

• Manually simulating different carb amounts (current workaround, see above).
• Using a fixed rule of thumb (e.g. 15 g), which ignores active insulin, active carbs, trend and individual settings.

Additional context
Screenshots attached: Add Carb Entry screen and Meal Bolus screen showing "No Bolus Recommended" during a low.