swarm-authelia: run the secret publisher and a journal forwarder inside the container

swarm-secret-publish and its path unit now run inside authelia's container,
beside the mint, and read each client secret at the path authelia writes it.
The host unit and host path unit, which read the secrets through the
container's root on the host, are gone, and so is
deploy.authelia.hostClientSecretDir, which only they read. The publisher keeps
its store identity, the secret-publisher leaf. The host hands the leaf and the
store's CA into the container as nspawn system credentials, and the unit loads
them; where this host mints the leaf, the container waits for swarm-bao-pki.
Authelia does not wait for the publisher, which retries every 30 seconds while
the store is down.

The container also runs the journal forwarder the other service containers
run, pushing to a receiver of its own on the swarm collector (serviceProducers
swarm-authelia) as a new machine OIDC client (swarm.authelia.otel.clientId)
that authelia registers for itself and the publisher carries to the store. The
fetch unit reads it back under the publisher's leaf, also handed to it as a
system credential, so the swarm-secret-publisher policy gains read on that one
leaf; its stanza keeps create and update, which the exact path would otherwise
take from the services/* prefix. Without the leaf the forwarder is off.

The container drops --link-journal=host, and the host collector stops reading
it. The services' "nothing at <path>" errors name the publisher in authelia's
container.

nix/host-modules/hive-forge/default.nix

@@ -40,7 +40,8 @@ let
   # root. Removed by the tmpfiles rule below.
   oldOidcSecretPath = "/var/lib/nixos-containers/hive-forge/var/lib/forgejo-oidc/${cfg.sso.clientId}.secret";
 
-  # Where swarm-secret-publish on authelia's host leaves this client's secret.
+  # Where swarm-secret-publish in authelia's container leaves this client's
+  # secret.
   # The forge publisher's store role grants read on this path.
   oidcStorePath = "secret/swarm/services/${cfg.sso.clientId}/oidc/client";
 
@@ -1196,8 +1197,8 @@ in
     # The forge's OIDC client secret, out of the swarm secret store under the
     # forge publisher's leaf — the one route, wherever authelia runs. Same
     # shape as ../hive-matrix.nix's `swarm-bao-matrix-oidc`: the login and the
-    # read both fail loudly, and `storeRetry` retries until the publisher on
-    # authelia's host has written the secret.
+    # read both fail loudly, and `storeRetry` retries until the publisher in
+    # authelia's container has written the secret.
     #
     # On the host, which reads that leaf from its own files. A host with no
     # publisher leaf fails here, naming the options, rather than rendering no