OG image endpoint crashes on invalid type query parameter

[tokiory]

Problem

src/routes/api/ogimg/+server.ts casts the type query parameter to keyof typeof IMAGE_SIZE without validating it:

const type = (url.searchParams.get('type') || 'opengraph') as keyof typeof IMAGE_SIZE;

A request such as /api/ogimg?type=bad makes IMAGE_SIZE[type] undefined. The endpoint then dereferences .upscale, .width, and .height, causing a runtime error.

Impact

Malformed requests can return a 500 from the OG image endpoint.

Expected

Unknown type values should either fall back to opengraph or return a controlled 400 response.

Suggested Fix

Validate type against IMAGE_SIZE before using it.