Agent host: SilverBullet boots into accounts and the vault, not a bare space

SB_NAME alone put SilverBullet 2.11 in single-space mode: no accounts, no
setup wizard, and its /data folder served instead of the vault. The compose
file sets only PUID and PGID now, a test holds it to that, and the host
check fails on a single-space boot.

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

deploy/agent-host/silverbullet/compose.yaml

@@ -8,9 +8,10 @@ services:
     image: ghcr.io/silverbulletmd/silverbullet:2.11.1-slim
     restart: unless-stopped
     environment:
+      # Only these. Any SB_* setting (even SB_NAME) boots a single space with
+      # no accounts, serving /data instead of the vault.
       PUID: "1000"
       PGID: "1000"
-      SB_NAME: Nisse vault
     ports:
       # IPv4 only; setup.sh's firewall lets only the operator's Caddy in.
       - "0.0.0.0:3000:3000"