feat: extend equipment and workout models with service tracking

internal/activity/parser.go

@@ -0,0 +1,18 @@
+package activity
+
+import "time"
+
+// ParsedActivity holds the extracted metrics from an activity file (FIT/TCX/GPX).
+type ParsedActivity struct {
+	Title          string
+	Duration       int       // seconds
+	Distance       float64   // kilometers
+	ElevGain       int       // meters
+	AvgPower       int       // watts
+	MaxPower       int       // watts
+	AvgHR          int       // bpm
+	MaxHR          int       // bpm
+	CaloriesBurned int       // kcal
+	AvgCadence     int       // rpm
+	StartTime      time.Time // activity start time
+}