feat(billing): sizes move up one; 1080p is the reference and the default

xs is a box with no stream, sm 720p, md 1080p, lg 1440p and xl 4K. Each
resolution keeps its price, so md is now 1x. New boxes default to md, and
existing boxes move up one size so none of them drops a resolution.

apps/api/app/routes/box.ts

@@ -41,7 +41,7 @@ export namespace BoxApi {
 				'json',
 				z.object({
 					label: z.string().trim().min(1).max(64).default('box'),
-					tier: z.enum(BoxTier.enumValues).default('sm'),
+					tier: z.enum(BoxTier.enumValues).default('md'),
 					on: z.enum(['own', 'fleet']).default('own')
 				})
 			),