v0.41.0

Minor bump: attach tickets (vgi.attach_tickets.v1 seal_attach, redemption of
vgi_attach_ticket in catalog_attach, Worker::signing_key, the reserved
attach-option name, CatalogModel::attach_payload) and the ticket_probe
fixture. Workspace version and the internal vgi-protocol / vgi-client pins
move in lockstep; vgi-rpc, vgi-rpc-client and vgi-rpc-iroh move to 0.31
(published). Cargo.lock is not tracked.

Co-Authored-By: Claude Opus 5.5 (1M context) noreply@anthropic.com