activity-stats: shared StatRow + canonical metrics across surfaces

Implements the activity-stats change (specs/activity-stats):

- gpx: `movingTime(tracks)` — moving seconds from trackpoint timestamps,
  excluding stationary spans + long gaps; null when no timestamps.
- stats.ts: pure formatters (distance/elevation/duration/speed/pace),
  sport-aware `deriveRate` (pace for foot sports, speed otherwise, speed
  default), and `activityStatItems` encoding the canonical order
  (distance · time · [moving] · pace/speed · ascent · descent; compact subset).
- StatRow: one shared presentational component (size sm/lg), adopted on the
  activity detail (full set; loader derives moving time), route detail
  (distance/ascent/descent), feed card + profile list (compact).
- i18n: journal.stats.* in en + de.

Tests: movingTime (stationary/gap exclusion, moving ≤ elapsed), deriveRate,
formatters, activityStatItems ordering + compact, StatRow render (jsdom).
typecheck + lint + unit (gpx 63, journal 311) green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

packages/gpx/src/index.ts

@@ -3,4 +3,5 @@ export { generateGpx } from "./generate.ts";
 export { extractWaypoints } from "./waypoints.ts";
 export { computeDays } from "./compute-days.ts";
 export type { DayStage } from "./compute-days.ts";
+export { movingTime } from "./moving-time.ts";
 export type { GpxData, TrackPoint, ElevationProfile, NoGoArea } from "./types.ts";

packages/gpx/src/moving-time.test.ts

@@ -0,0 +1,56 @@
+import { describe, it, expect } from "vitest";
+import { movingTime } from "./moving-time.ts";
+import type { TrackPoint } from "./types.ts";
+
+// ~0.0001° latitude ≈ 11.1 m. At 11 m per interval, speed depends on dt.
+function pt(lat: number, lon: number, time?: string): TrackPoint {
+  return { lat, lon, time };
+}
+
+describe("movingTime", () => {
+  it("returns null when no trackpoints carry timestamps", () => {
+    const tracks = [[pt(0, 0), pt(0, 0.0001), pt(0, 0.0002)]];
+    expect(movingTime(tracks)).toBeNull();
+  });
+
+  it("sums intervals where the athlete is moving", () => {
+    // Three points 10s apart, each ~11 m → ~1.1 m/s (moving). 2 intervals.
+    const tracks = [[
+      pt(0, 0, "2026-06-01T08:00:00Z"),
+      pt(0, 0.0001, "2026-06-01T08:00:10Z"),
+      pt(0, 0.0002, "2026-06-01T08:00:20Z"),
+    ]];
+    expect(movingTime(tracks)).toBe(20);
+  });
+
+  it("excludes stationary spans (below the speed threshold)", () => {
+    // Middle interval: no movement over 10s → stopped, excluded.
+    const tracks = [[
+      pt(0, 0, "2026-06-01T08:00:00Z"),
+      pt(0, 0.0001, "2026-06-01T08:00:10Z"), // moving (~11 m / 10s)
+      pt(0, 0.0001, "2026-06-01T08:00:20Z"), // stationary (0 m)
+      pt(0, 0.0002, "2026-06-01T08:00:30Z"), // moving again
+    ]];
+    expect(movingTime(tracks)).toBe(20); // 2 moving intervals of 10s
+  });
+
+  it("excludes long gaps (pauses / signal loss)", () => {
+    const tracks = [[
+      pt(0, 0, "2026-06-01T08:00:00Z"),
+      pt(0, 0.0001, "2026-06-01T08:00:10Z"), // 10s moving
+      pt(0, 0.0002, "2026-06-01T09:00:00Z"), // ~1h gap → excluded
+    ]];
+    expect(movingTime(tracks)).toBe(10);
+  });
+
+  it("never exceeds elapsed time", () => {
+    const tracks = [[
+      pt(0, 0, "2026-06-01T08:00:00Z"),
+      pt(0, 0.0001, "2026-06-01T08:00:10Z"),
+      pt(0, 0.0001, "2026-06-01T08:00:40Z"), // 30s stationary
+    ]];
+    const elapsed = 40;
+    const moving = movingTime(tracks)!;
+    expect(moving).toBeLessThanOrEqual(elapsed);
+  });
+});

packages/gpx/src/moving-time.ts

@@ -0,0 +1,46 @@
+import type { TrackPoint } from "./types.ts";
+
+// Below this speed we treat the athlete as stopped (traffic lights, photo
+// stops, regroups). 0.5 m/s ≈ 1.8 km/h — slower than a slow walk.
+const STATIONARY_SPEED_MS = 0.5;
+// Intervals longer than this are pauses or GPS gaps, not continuous motion;
+// they're excluded entirely so a lunch break doesn't inflate moving time.
+const MAX_GAP_S = 60;
+
+function haversineMeters(lat1: number, lon1: number, lat2: number, lon2: number): number {
+  const R = 6371000;
+  const toRad = (d: number) => (d * Math.PI) / 180;
+  const dLat = toRad(lat2 - lat1);
+  const dLon = toRad(lon2 - lon1);
+  const a =
+    Math.sin(dLat / 2) ** 2 +
+    Math.cos(toRad(lat1)) * Math.cos(toRad(lat2)) * Math.sin(dLon / 2) ** 2;
+  return R * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
+}
+
+/**
+ * Moving time in seconds, derived from trackpoint timestamps: the sum of
+ * inter-point intervals during which the athlete was actually moving
+ * (excluding stationary spans and long gaps). Returns `null` when the track
+ * has no usable timestamps (planned routes, or recordings without time), so
+ * callers can fall back to elapsed time. Moving time is always ≤ elapsed.
+ */
+export function movingTime(tracks: TrackPoint[][]): number | null {
+  let movingSeconds = 0;
+  let timedIntervals = 0;
+
+  for (const seg of tracks) {
+    for (let i = 1; i < seg.length; i++) {
+      const prev = seg[i - 1];
+      const cur = seg[i];
+      if (!prev || !cur || !prev.time || !cur.time) continue;
+      const dt = (Date.parse(cur.time) - Date.parse(prev.time)) / 1000;
+      if (!Number.isFinite(dt) || dt <= 0 || dt > MAX_GAP_S) continue;
+      timedIntervals++;
+      const speed = haversineMeters(prev.lat, prev.lon, cur.lat, cur.lon) / dt;
+      if (speed >= STATIONARY_SPEED_MS) movingSeconds += dt;
+    }
+  }
+
+  return timedIntervals > 0 ? Math.round(movingSeconds) : null;
+}

packages/i18n/src/locales/de.ts

@@ -396,6 +396,15 @@ export default {
         public: "Öffentlich (für alle sichtbar)",
       },
     },
+    stats: {
+      distance: "Distanz",
+      duration: "Zeit",
+      movingTime: "Bewegungszeit",
+      avgSpeed: "⌀ Geschwindigkeit",
+      avgPace: "⌀ Pace",
+      ascent: "Anstieg",
+      descent: "Abstieg",
+    },
     settings: {
       title: "Einstellungen",
       nav: {

packages/i18n/src/locales/en.ts

@@ -396,6 +396,15 @@ export default {
         public: "Public (anyone on the internet)",
       },
     },
+    stats: {
+      distance: "Distance",
+      duration: "Time",
+      movingTime: "Moving time",
+      avgSpeed: "Avg speed",
+      avgPace: "Avg pace",
+      ascent: "Ascent",
+      descent: "Descent",
+    },
     settings: {
       title: "Settings",
       nav: {