swarm CA: describe the store's pki root as the only anchor in docs and comments

The docs, option descriptions and comments that named the swarm root, the
swarm CA or the hive CA as an existing trust anchor now name the secret
store's pki root or the trust bundle that holds it:

- docs/swarm/README.md, secrets.md, bao.md
- deploy.bao.clientCaFile's and gateway.verifiedProxyTo's descriptions
- comments in hive-c0re/src/meta.rs, hive-agent/src/swarm_queue.rs,
  swarm-logs/src/auth.rs, swarm-controller/src/vcs_metrics.rs,
  hive-forge, swarm-authelia, swarm-ci-runner, glue-bao-tls, swarm-bao,
  swarm-grafana, swarm-otel, otel, hive-c0re, lib/hive-ca-trust.nix,
  hive-forge/Cargo.toml and the flake-update workflow

Nothing behaves differently: every edit is a nix, Rust or TOML comment, an
option description, or a test assertion message. The Rust edits change the
workspace source, which this PR already rebuilds for hivectl.

Refs #4588

nix/host-modules/swarm-authelia.nix

@@ -97,9 +97,8 @@ let
     tlsCfg = deployCfg.hive-controller.tls;
   };
   # `swarm-authelia-bridge` verifies the gateway when it introspects by name.
-  # Nothing in this container trusted the swarm CA, which is a runtime file no
-  # build-time option can name — so an https call out of here could only ever
-  # fail `UnknownIssuer`. Same defect the queue's responder hit.
+  # The store's `pki` root is a runtime file no build-time option can name, so
+  # without this bundle an https call out of here fails `UnknownIssuer`.
   caBundleModule = caTrust.trustBundle {
     inherit pkgs;
     name = cfg.machine;