openspec: propose journal route/activity detail catch-up changes

Three OpenSpec proposals to bring the journal's route/activity detail and feed
closer to best-in-class outdoor apps, in the order we'll implement them:

- activity-sport-type: nullable sport enum on activities (hike/walk/run/
  ride/gravel/mtb/ski/other), set on create or normalized on import,
  shown as a badge + feed verb, federated as a Note PropertyValue.
- activity-stats: one reusable StatRow + canonical metric set, sport-aware
  avg pace/speed, moving-vs-elapsed time. Derive-only, no schema change.
- journal-elevation-profile: elevation profile chart + chart<->map
  "active distance" hover/click sync on the read-only detail pages.

All three validate with `openspec validate --strict`. Specs only; no code.

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

openspec/changes/activity-stats/tasks.md

@@ -0,0 +1,27 @@
+## 1. Helpers
+
+- [ ] 1.1 Add a pure `movingTime(gpx)` helper to `@trails-cool/gpx` (sum inter-point intervals, exclude sub-threshold/stationary segments, max-gap guard); unit-test against fixtures with and without trackpoint times.
+- [ ] 1.2 Add a `deriveRate({ distance, time, sportType })` helper returning `{ kind: "pace" | "speed", value }` with the sport→kind rule and speed default.
+- [ ] 1.3 Add a `formatStat` helper (distance/elevation/time/speed/pace) routing labels + units through i18n.
+
+## 2. Component
+
+- [ ] 2.1 Build the shared `StatRow` (ordered `{ value, label, unit }` items; value-prominent layout; no data fetching).
+- [ ] 2.2 Define the canonical headline order as a single exported constant the surfaces draw from.
+
+## 3. Adopt across surfaces
+
+- [ ] 3.1 Activity detail: replace the hand-rolled stats block with `StatRow` (full set incl. pace/speed + moving/elapsed).
+- [ ] 3.2 Route detail: adopt `StatRow` (distance, ascent, descent; no time/pace).
+- [ ] 3.3 Feed card: adopt `StatRow` compact subset (distance · time · pace/speed); expose the needed fields in the feed loader.
+- [ ] 3.4 Profile activity list: adopt `StatRow` compact subset.
+
+## 4. i18n
+
+- [ ] 4.1 Add `journal.stats.*` keys (labels + unit suffixes for distance, elevation, time, speed, pace) to en + de.
+
+## 5. Tests & checks
+
+- [ ] 5.1 Unit: `movingTime` (with/without timestamps; moving ≤ elapsed), `deriveRate` (pace/speed/default), `formatStat`.
+- [ ] 5.2 Component: `StatRow` renders ordered items; subset preserves order.
+- [ ] 5.3 `pnpm typecheck && pnpm lint && pnpm test && pnpm test:e2e` green.