Add avg power and NP to activity summary; NP uses Coggan 30s rolling-average method

site/src/components/ActivityDetail.svelte

@@ -123,6 +123,10 @@
     stat('Avg HR',      activity.avg_hr_bpm ? `${activity.avg_hr_bpm} bpm` : '—',     'heart_rate'),
     stat('Max HR',      activity.max_hr_bpm ? `${activity.max_hr_bpm} bpm` : '—',     'heart_rate'),
     stat('Cadence',     activity.avg_cadence_rpm ? `${activity.avg_cadence_rpm} rpm` : '—', 'cadence'),
+    ...(activity.avg_power_w != null ? [
+      stat('Avg power', `${activity.avg_power_w} W`,                               'power'),
+      stat('NP',        detail?.np_power_w != null ? `${detail.np_power_w} W` : '—', 'power'),
+    ] : []),
   ].filter(s => !s.key || !hiddenStats.has(s.key));
 </script>
 

site/src/lib/types.ts

@@ -109,6 +109,7 @@ export interface Timeseries {
 export interface ActivityDetail extends Omit<ActivitySummary, 'detail_url' | 'track_url' | 'preview_coords'> {
   description: string | null;
   elevation_loss_m: number | null;
+  np_power_w: number | null;
   max_power_w: number | null;
   gear: string | null;
   device: string | null;