# GTR011 — Upgrade25_1: drop `<trackster_conf>` (25.1 → 26.0)

**Contract:** behaviour-preserving in the target era (dead-config removal).

## The delta
26.0 removes the obsolete top-level `<trackster_conf>` element (the Trackster
visualization config) from the schema.

## The transform
Remove every `<trackster_conf>` element.

## Proof
The element configures a subsystem that no longer exists in the Galaxy era the
upgraded tool declares (`profile="26.0"+`): no 26.0-era code path consumes it,
so removal is a runtime no-op *there* — and it is the only way to validate at
26.0. The pre-upgrade behaviour (Trackster on ancient Galaxies) is exactly what
the opt-in `upgrade` contract trades away, surfaced via `behavior_preserving`.

## History
Codemod §14; discovery-sweep grown.