Audit follow-ups on the secondary-account retry.
The accounts snapshot is written by the heartbeat task and, now, by the
retry loop. Both used one fixed tmp path, so concurrent writers could
clobber it or fail the rename. Each write now names its own tmp file
(pid + counter); a test hammers it from four threads.
A permanently bad secondary logged three warnings per attempt, every 16
minutes, for as long as the daemon ran. DownAccounts::failed now reports
whether a failure is news (first, or a different reason from the last);
only that is a warning, repeats are debug. The two per-attempt warnings
in client.rs and credential.rs are covered by that line, which names the
reason, so the store-token one drops to debug.
The comments in client.rs and a credential.rs test, and persistence.md,
still described the old skip-until-restart behaviour or implied that a
store-listed account without a credential is retried here; that case is
handled by the linked-name set changing, not by this loop.
An agent's matrix encryption keys lived only in its local crypto store, so
`destroy --purge` or a primary-account token reset lost every encrypted
room's history with no way back (#5022).
swarm-controller now mints a random passphrase (32 bytes from the kernel's
CSPRNG, base64url) for every account listed under each agent's `matrix/`
directory, at `swarm/agents/<agent>/matrix-recovery/<account>`, in a
five-minute pass. The write is a cas=0 create after a read; a path that
holds anything is never replaced, and a create that loses a race counts as
done. The controller's existing `data/swarm/agents/*` grant covers the
write and the agent's own `agents/<agent>/*` read grant covers the read, so
no policy changes.
hive-matrix-daemon reads the passphrase when it brings an account up, after
cross-signing: with no backup on the homeserver it enables recovery with it
(backup + secret storage); with one there it recovers, which imports the
backup key and the self-signing key, and room keys then download through
`BackupDownloadStrategy::OneShot`. No passphrase yet logs at INFO and the
account comes up without backup; any failure logs WARN and never stops the
daemon.
Recovery runs after `ensure_cross_signing`, not before: on a new account
cross-signing must exist locally for `enable` to export it into secret
storage, and on an existing identity `bootstrap_cross_signing_if_needed` is
a no-op, leaving `recover` to import and sign.
Part of #5022 (S1+S2, with the S4 docs).
hive-matrix-daemon now learns which external matrix accounts it has from
the swarm secret store, under the agent's own certificate, and the hive
push chain for matrix is gone.
The daemon lists swarm/agents/<agent>/matrix/ (the `list` its policy
grants on its own metadata subtree), reads each account's homeserver
from its credential, and brings the accounts up with their tokens from
the store. Every two minutes it lists again and exits with 75 when the
set of linked accounts changed; the unit restarts on 75 without counting
a failure. A listed name whose credential reads as absent is skipped and
logged once. At start it removes the matrix-token-<a> /
matrix-account-<a>.json pairs a hive delivered (a sidecar marks a pair
as delivered; a declared tokenFile keeps its token).
Removed: CredentialNotice and the $SWARM.credential.* subject and NATS
grant, the controller's publish and its queue precondition on the PUT
route, hive-c0re's credential subscription arm and workers/credential.rs,
priv_client::write_agent_matrix_token, hive-priv's WriteAgentMatrixToken
and its helpers, and the daemon's state-dir account discovery.
Kept: WriteAgentGithubToken and the external-forge path
(WriteAgentExtraForgeAccount, extra_forges.rs) are untouched, and a
declared matrixAccounts tokenFile is still read when the store has no
token for that account.
Refs #4348
The daemon reads each account's token from `swarm/agents/<agent>/matrix/`
as the agent itself, inside its own container, and falls back to the file
only when the store has none. This is #4519's read, without its `main`
carve-out: the swarm now mints `main` there and no hive writes the file.
The daemon unit gets the agent's store identity, spelled the way
forge-token.nix spells it. A timer re-starts it while it is down: a token
the swarm mints or replaces in the store changes no file, so the path
watcher never fires for it, and a daemon that exited on a replaced token
would otherwise stay down until the container restarts.
