Refreshes the vendored lexicon JSON files under priv/lexicons from
their upstream sources and records the pinned revisions in
priv/lexicons/SOURCES.md.
Sources:
app/bsky/**: the full corpus from github.com/bluesky-social/atproto at the latestmaincommit (the resolved commit is recorded)community/**: full corpus. The file list comes from the GitHub mirror (lexicon-community/lexicon); every file downloads from Tangled, the canonical source. New community lexicons appear on the next sync.com/atproto/**: refresh-in-place. Only the files already vendored are re-downloaded, keeping the curated set intentional; new com.atproto schemas are added by hand when a generated lexicon needs them
After syncing, run mix exosphere.gen.lexicons to regenerate modules and
review the diff.