Feature Request: Manual hydration tracking with daily goal counter

[gerageragarza-prog]

Summary / Resumen

EN: Add a manual hydration tracker that lets the user log water intake throughout the day and see progress toward a daily goal.

ES: Agregar un contador manual de hidratación que permita registrar el consumo de agua a lo largo del día y ver el progreso hacia una meta diaria.

Motivation / Motivación

EN: The band doesn't measure hydration directly, but it's a metric that directly affects recovery, HRV, and strain tolerance. A simple manual log (tap to add a glass/bottle, set a daily target in ml/oz) would let users correlate hydration with recovery trends already tracked in the Journal feature, without requiring any new hardware sensor.

ES: La banda no mide hidratación directamente, pero es una métrica que afecta directamente el recovery, el HRV y la tolerancia al esfuerzo. Un registro manual simple (tocar para agregar un vaso/botella, definir una meta diaria en ml/oz) permitiría correlacionar la hidratación con las tendencias de recovery que ya se rastrean en el Journal, sin necesitar ningún sensor nuevo.

Proposed behavior / Comportamiento propuesto

• Set a daily hydration goal (ml or oz, user's choice of unit)
• Quick-add buttons for common amounts (e.g. 250ml / 8oz glass, custom amount)
• Visual progress indicator (ring or bar) showing intake vs. goal, similar to the existing ring-style indicators used for Strain/Recovery/Sleep
• Daily reset at midnight (or user-defined day boundary, consistent with existing sleep/day logic)
• Historical log viewable in Trends, so it can be cross-referenced with recovery/HRV over time
• Optional: surface hydration as a factor in the Journal's correlation insights ("what actually moves your numbers")

Alternatives considered / Alternativas consideradas

EN: Could live as a widget-only feature, but full app integration with Trends/Journal would add more long-term value since it enables correlation analysis.

ES: Podría implementarse solo como widget, pero la integración completa con Trends/Journal aportaría más valor a largo plazo al permitir análisis de correlación.

Additional context / Contexto adicional

This wouldn't require any new BLE/protocol work since it's fully manual input — should be isolated to lib/ui/ and lib/data/ (local storage) per the repo layout.