refactor(server::actors::vault): clean up Bootstrap/TryUnseal, remove Bootstrapping state

Bootstrap and TryUnseal now accept a SafeCell<Vec<u8>> seal key directly.
The Bootstrapping intermediate state is removed — multi-operator coordination
is the responsibility of VaultCoordinator, which calls Bootstrap atomically
once all shares are collected.

server/crates/arbiter-server/src/grpc/operator/vault.rs

@@ -47,7 +47,6 @@ async fn handle_query_vault_state(
     let state = match actor.ask(HandleQueryVaultState {}).await {
         Ok(VaultState::Unbootstrapped) => ProtoVaultState::Unbootstrapped,
         Ok(VaultState::Sealed) => ProtoVaultState::Sealed,
-        Ok(VaultState::Bootstrapping) => ProtoVaultState::Boostrapping,
         Ok(VaultState::Unsealed) => ProtoVaultState::Unsealed,
         Err(err) => {
             warn!(error = ?err, "Failed to query vault state");