`discoverInstalledCollections` probed all ~220 known collection names with
`isPackageExists('@iconify-json/<name>')`. Each *missing* name triggers a full
module resolution that walks `node_modules` up to the filesystem root, so on a
project with few/no `@iconify-json` packages this loop takes ~0.8–1.9s.

The server bundle is generated lazily on the first dev request, so that cost
lands on the cold first page load even when no icon is rendered (`server` is the
SSR-default provider). Measured ~862ms on a fresh app; switching the provider to
`iconify` (which skips this path) removed the same ~0.6s.

Instead, list the `@iconify-json` scope directory across `node_modules` (walking
up from each resolve path) once, validate each entry ships an `icons.json`, and
intersect with the known list — behaviour-equivalent, ~3ms. Yarn PnP (no
`node_modules` to read) falls back to the resolver probe.