Strava connector (mcp.strava.com/mcp) missing gear_id

### What happened?

list_activities (and likely get_activity_performance) never returns the gear_id field for any activity, even though the tool's own description says it should be included, and even when gear is correctly tagged on the activity in Strava itself. Confirmed by tagging a bike on an activity in Strava directly — the tag shows correctly on strava.com, but the MCP's list_activities response for that activity still omits gear_id entirely.

### What did you expect to happen?

gear_id should be populated when an activity has gear tagged in Strava.

### Steps to reproduce

Steps to reproduce:

In Strava, tag an activity with a gear item (e.g. a bike) via the activity's Edit screen so it's correctly linked in Strava's gear field.
In Claude, call the Strava MCP's list_activities tool (or get_activity_performance) with include_tags: true.
Observe the returned JSON for that activity.

### Area

Tool Discovery / Invocation

### MCP Server (if applicable)

mcp.strava.com/mcp

### Error messages or logs

```shell
No error thrown — call returns successfully but silently omits the field.
Raw response for that activity:

json
{
"id": "19718464758",
"name": "Mountain Bike Ride",
"description": "Bike: Trail",
"sport_type": "MountainBikeRide",
"start_local": "2026-08-12T18:00:14",
"is_trainer": false,
"summary": {
"distance": 15994.4,
"moving_time": 4510,
"elapsed_time": 4969,
"elevation_gain": 140,
"avg_speed": 3.546430155210643,
"max_speed": 8,
"relative_effort": 95,
"total_calories": 622,
"kudos_count": 1,
"achievement_count": 2,
"pr_count": 2
}
}

Note: no gear_id, no activity_tags, no is_commute — all three were requested via include_tags: true and all three are missing.
```

### Additional context

_No response_