[Feature]: Deduplicate step calories when a workout session is active (Garmin double-counting)

[Soulplayer]

Is your feature request related to a problem? Please describe.

When Garmin syncs data to SparkyFitness, step calories and workout calories are counted separately, resulting in double-counting. For example, when logging a 7km run as a workout session (572 cal), the steps from that same run are also counted via the step counter (15,830 steps = 633 cal), inflating total burned calories by ~633 cal. This makes the daily calorie goal too generous and can undermine weight loss efforts.

Describe the solution you'd prefer

SparkyFitness should detect overlapping timestamps between workout sessions and step data from Garmin. When a workout session is active, steps recorded during that time window should not be added on top of the workout calories, as they represent the same physical activity.

Additional context

This is similar to how Apple Health and MyFitnessPal handle Garmin data — they deduplicate activity calories when a workout session overlaps with passive step tracking. A similar deduplication logic in SparkyFitness would make calorie calculations significantly more accurate for users who wear their Garmin during workouts.

Using Device Projection mode with a Garmin Epix Pro. Steps and workouts both sync automatically via Garmin Connect integration.