v0.4: ### Notable changes

Notable changes

• Migrate to ATProto repo v3. Specifically, the existing subscribeRepos sequence number is reused as the new rev field in commits. (Discussion.).
• Add new did module with utilities to create and resolve did:plcs and resolve did:webs.
• Add new util.service_jwt function that generates ATProto inter-service JWTs.
• Repo:
  • Add new signing_key/rotation_key attributes. Generate store, and load both in datastore_storage.
  • Remove format_init_commit, migrate existing calls to format_commit.
• Storage:
  • Rename read_from_seq => read_blocks_by_seq (and in MemoryStorage and DatastoreStorage), add new read_commits_by_seq method.
  • Merge load_repo did/handle kwargs into did_or_handle.
• XRPCs:
  • Make subscribeRepos check storage for all new commits every time it wakes up.
    • As part of this, replace xrpc_sync.enqueue_commit with new send_new_commits function that takes no parameters.
  • Drop bundled app.bsky/com.atproto lexicons, use lexrpc's instead.