# V3-14 — GPX interoperability

**Phase** Quality · **Depends on** V3-01 for `<type>` · **Size** S · **Status** Not started

## Goal
Confirm an exported ride actually imports into Strava, Garmin Connect and Google Earth —
and add the activity type so it lands as the right kind of activity.

## Context
Export is well tested: 15 tests, parsed with a real XML parser, and **byte-identical to the
Kotlin original** under the parity harness. But every one of those tests proves *structural
validity*, and structural validity does not mean a consumer accepts the file. That gap has
been open since v2.

## Design
Two parts.

**Verification** — export a real ride and import it into each of Strava, Garmin Connect and
Google Earth. Record what each does with pauses, elevation and timestamps. Pauses are the
interesting case: `<trkseg>` per segment is the correct GPX representation, but consumers
vary in whether they honour it.

**`<type>` on `<trk>`** — Strava and Garmin read it to decide the activity. Without it a
bicycle ride may import as a run. Needs V3-01's activity, mapped to each consumer's
vocabulary (Strava uses `ride`, `run`, and so on).

## Implementation
1. Add `<type>` to the `<trk>` element, from the trip's activity
2. Map the internal enum to GPX conventions; document the mapping in the code
3. Export a real multi-segment ride and import it into all three consumers
4. Write the findings into this file, including anything that surprises

## Acceptance criteria
- [ ] A real ride imports into Strava with the right activity type
- [ ] It imports into Garmin Connect
- [ ] It opens in Google Earth with the path in the right place
- [ ] Pause behaviour in each consumer is documented, whatever it turns out to be
- [ ] Existing export tests still pass, including the byte-identical parity check —
      **this one will need updating, since `<type>` changes the output**

## Tests
- `<type>` present and correct per activity
- Absent, not empty, when the activity is `other`
- **The parity harness will now differ from Kotlin here. That is expected and correct —
  update its expectation and note why, rather than dropping the check.**

## Risks
Silently breaking the parity harness by changing export output. Update it deliberately.

## Out of scope
GPX import into Rippr. FIT and TCX formats.