The existing POST /update/ replaces all fields — omitted fields are
reset to defaults (e.g. envVars becomes [], instanceCount becomes 0).
This makes simple operations like scaling dangerous: sending only
{appName, instanceCount} wipes all environment variables.
The new PATCH /update/ endpoint fetches the existing app definition
and merges only the explicitly provided fields. Omitted fields retain
their current values.
Example — scale without touching env vars:
PATCH /api/v2/user/apps/appDefinitions/update/
{"appName": "my-app", "instanceCount": 1}
The POST endpoint is unchanged — full backward compatibility.
Ivn Nv