- Add `rekey.proto` with `ContributePassphrase` / `ContributeRecoveryPassphrase` / `RekeyResult`
- Wire `rekey` as a 4th vault stream payload in `vault.proto` and gRPC dispatch
- Add `RekeyRootKey` message to `Vault` actor: generates new random seal key, re-encrypts root key, writes new `root_key_history` row
- Add `StartRekey`, `ContributeRekey`, `ContributeRecoveryRekey` messages to `VaultCoordinator`; `finalize_rekey` uses threshold-1 fast path identical to bootstrap
- `execute_replace_operator` now UPDATEs `operator_identity.public_key` in-place (avoids FK constraint violation), deletes stale `operator` share row, then triggers `StartRekey`
- `execute_update_shamir_parameters` triggers `StartRekey` instead of warning stub
- `ProposalKind::ReplaceOperator` carries `old_operator_id`; encode/decode updated accordingly
- `GlobalActors::spawn` extracts `vault_coordinator` before `Ok(Self { … })` so it can be cloned into `ProposalManager::new`
- Add `handle_rekey` in session handlers forwarding passphrase contributions to `VaultCoordinator`
- Fix test: rename `replace_operator_inserts_identity_row` → `replace_operator_updates_pubkey_and_starts_rekey`, assert count stays 1 and pubkey is updated
Adds DeclareCommittee and ContributePassphrase variants to bootstrap.proto,
ContributePassphrase to unseal.proto, and AwaitingContributions result codes
to both. Implements corresponding inbound converters and outbound reply
mappings. VaultGate handlers delegate to VaultCoordinator.
VaultCoordinator collects operator passphrases, splits the seal key into
Shamir shares on bootstrap (encrypting each share with the operator's
passphrase via Argon2 + XChaCha20-Poly1305), and reconstructs the seal
key from threshold shares on unseal. Adds vsss-rs 5.4.0 and rand_core 0.6
dependencies.
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.
