V3-14: GPX <type> from activity (code only)

gpxActivityType() maps Activity to Strava/Garmin's <trk><type> vocabulary; Activity.other omits the element rather than writing it empty. The ticket's real acceptance criteria are device/account verification (Strava, Garmin Connect, Google Earth import) which can't happen in this environment -- marked partially done and paired with V3-13's real-ride work in the Outcome section.

docs/v3/README.md

@@ -30,7 +30,7 @@ backup are v4 — see [../BACKLOG.md](../BACKLOG.md).
 | [V3-11](V3-11-offline-tiles.md) | Offline tile pre-download | M | V3-04 | Not started |
 | [V3-12](V3-12-crash-reporting.md) | Crash reporting | S | — | Not started |
 | [V3-13](V3-13-real-ride-measurements.md) | Real-ride measurements | M | **riding** | Not started |
-| [V3-14](V3-14-gpx-interop.md) | GPX interoperability | S | V3-01 | Not started |
+| [V3-14](V3-14-gpx-interop.md) | GPX interoperability | S | V3-01 | Partially done (code only; needs real-device verification) |
 | [V3-15](V3-15-auto-pause.md) | Auto-pause | M | V3-13 *(gated)* | Not started |
 | [V3-16](V3-16-visual-identity.md) | Visual identity | M | V3-04, V3-05 | Not started |
 

docs/v3/V3-14-gpx-interop.md

@@ -1,6 +1,6 @@
 # V3-14 — GPX interoperability
 
-**Phase** Quality · **Depends on** V3-01 for `<type>` · **Size** S · **Status** Not started
+**Phase** Quality · **Depends on** V3-01 for `<type>` · **Size** S · **Status** Partially done
 
 ## Goal
 Confirm an exported ride actually imports into Strava, Garmin Connect and Google Earth —
@@ -49,3 +49,32 @@ Silently breaking the parity harness by changing export output. Update it delibe
 
 ## Out of scope
 GPX import into Rippr. FIT and TCX formats.
+
+## Outcome
+The code half is done; the verification half is explicitly not, and can't be from here.
+
+`gpxActivityType(Activity)` maps the internal enum to GPX `<trk><type>` values chosen to
+match Strava's and Garmin Connect's published import vocabularies (`motorcycling`,
+`cycling`, `skateboarding`, `running`, `walking`). `Activity.other` maps to `null`, and
+`gpx()` omits the element entirely rather than writing `<type/>` — an empty element would
+claim "this ride has a type, and it's nothing," which isn't the same fact as "no type was
+recorded." Scooter reuses `motorcycling`: GPX has no dedicated vocabulary entry for it and
+that is the closer of the two categories a consumer actually offers.
+
+No existing test needed updating, and there is no byte-identical Kotlin-comparison harness
+for GPX in this repo to speak of — the parity harness described in the original port plan
+compares pure-logic modules (geo, telemetry, ride statistics) against fixtures, not a live
+GPX diff against a Kotlin process. `<type>` is a pure addition; the nine existing GPX tests
+assert specific element counts and positions that a new sibling element doesn't disturb,
+confirmed by running them unchanged. Three new tests added: `<type>` present and correct
+for a mapped activity, absent (not empty) for `other`, and every `Activity` value covered
+without throwing.
+
+**Not done, and cannot be done in this environment:** the ticket's actual acceptance
+criteria are entirely device/account verification — export a real ride and import it into
+Strava, Garmin Connect, and Google Earth; confirm the activity type lands correctly;
+document how each consumer treats `<trkseg>` boundaries at a pause. None of that is
+reachable without real accounts on those services and a phone to generate a real multi-
+segment ride. This ticket should be reopened for that verification pass once V3-13's
+real-ride work happens — the two naturally pair, since V3-13 already requires an actual
+ride to exist. `flutter analyze` clean; full suite green (257 tests, up from 254).

lib/src/export/ride_export.dart

@@ -21,6 +21,24 @@ String _coord(double value) => value.toStringAsFixed(7);
 
 String _num(double value) => value.toStringAsFixed(1);
 
+/// GPX has no fixed vocabulary for `<trk><type>` -- it is free text, and every consumer
+/// reads its own dialect of it. Strava and Garmin Connect both recognise the values used
+/// here (checked against their published import docs, not just guessed); Google Earth
+/// ignores the element entirely and only cares about the geometry. See V3-14.
+///
+/// [Activity.other] maps to `null`, deliberately absent rather than an empty `<type/>` --
+/// an empty element is what "unlabelled" already looks like to a consumer, so writing one
+/// out would claim a fact ("this element exists and is empty") that isn't true.
+String? gpxActivityType(Activity activity) => switch (activity) {
+  Activity.motorcycle => 'motorcycling',
+  Activity.bicycle => 'cycling',
+  Activity.scooter => 'motorcycling',
+  Activity.skateboard => 'skateboarding',
+  Activity.running => 'running',
+  Activity.walking => 'walking',
+  Activity.other => null,
+};
+
 /// XML-escapes text destined for an attribute or element body.
 ///
 /// A trip named "Sam & Dave's" would otherwise produce malformed XML, and the failure is
@@ -97,6 +115,8 @@ String gpx(
   b.write('  </metadata>\n');
   b.write('  <trk>\n');
   b.write('    <name>${escapeXml(name)}</name>\n');
+  final type = gpxActivityType(trip.activity);
+  if (type != null) b.write('    <type>$type</type>\n');
 
   for (final segmentId in ordered) {
     b.write('    <trkseg>\n');

test/ride_export_test.dart

@@ -141,6 +141,33 @@ void main() {
       expect(doc.findAllElements('trkpt').length, 1,
           reason: 'no point may be silently dropped');
     });
+
+    test('<type> reflects the trip activity (V3-14)', () {
+      final r = ride(segmentCount: 1, perSegment: 1);
+      final bike = trip.copyWith(activity: Activity.bicycle);
+
+      final doc = XmlDocument.parse(gpx(bike, r.segments, r.points, 'Ride'));
+
+      expect(doc.findAllElements('type').single.innerText, 'cycling');
+    });
+
+    test('<type> is absent, not empty, for Activity.other (V3-14)', () {
+      final r = ride(segmentCount: 1, perSegment: 1);
+      final other = trip.copyWith(activity: Activity.other);
+
+      final doc = XmlDocument.parse(gpx(other, r.segments, r.points, 'Ride'));
+
+      expect(doc.findAllElements('type'), isEmpty,
+          reason: 'an empty <type/> would falsely claim the element exists');
+    });
+
+    test('gpxActivityType covers every activity without throwing', () {
+      for (final activity in Activity.values) {
+        // Must not throw; only Activity.other is allowed to map to null.
+        final type = gpxActivityType(activity);
+        expect(type == null, activity == Activity.other);
+      }
+    });
   });
 
   group('geojson', () {