Agent host: SilverBullet serves the vault as its one space, behind Authelia

The operator chose single-space mode: the vault is mounted at /data, with
memory/ read-only over it, and there are no accounts or setup wizard;
Authelia in the operator's Caddy is the login. SB_NAME forces the mode, so
an empty vault can't boot the wizard. SilverBullet's own data folder is
gone. check now fails if the wizard could be open. The README says how to
make memory/ writable for a while and back.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

docs/Development-Plan.md

@@ -535,15 +535,18 @@ early on the agent host (`deploy/agent-host`), so the operator can keep material
 for `nisse-ops` there now:
 - The vault is `/srv/nisse/vault`. The operator owns its root and everything in
   it but `memory/`, the agents'; `infrastructure/` is the operator's material
-  for `nisse-ops`. SilverBullet mounts the vault and, over it, `memory/`
-  read-only, and nothing else of the host but its own data.
+  for `nisse-ops`. SilverBullet serves the vault as its one space (single-space
+  mode, mounted at `/data`), with `memory/` mounted over it read-only, and sees
+  nothing else of the host.
 - SilverBullet's version is pinned (the docker role updates images nightly).
-  Its accounts are its own, made in its setup wizard.
+  It has no accounts and no setup wizard; `SB_NAME` forces single-space mode,
+  so an empty vault can't boot the wizard.
 - Decided with the operator: behind their Caddy at `nisse-memory.dongar.net` for
-  HTTPS, inside garrett-hall.com only, with no Authelia (an internal instance;
-  SilverBullet's own login is enough), and its own instance rather than the operator's personal one, so
-  the vault stays one local copy with mounts enforcing its writers. On the host,
-  a `DOCKER-USER` rule lets only Caddy reach it.
+  HTTPS, reachable from anywhere through Authelia, which is the login (agents
+  never go through SilverBullet, so this changes only the operator's access).
+  Its own instance rather than the operator's personal one, so the vault stays
+  one local copy with mounts enforcing its writers. On the host, a
+  `DOCKER-USER` rule lets only Caddy reach it, so nothing gets around Authelia.
 
 ### Phase 6 — Production