docs: publish Preview 19 dogfood evidence

Export the reviewed allowlisted snapshot from private source commit 05928cebd01b586cf9e9d4b8c8537a7605a6068c. This records the exact candidate, bounded capacity result, stateful migration scratch requirement, authenticated batch identity proof, and immediate live acceptance evidence.

AI-Assisted: OpenAI Codex
Signed-off-by: Cole Speelman <crspeelman@gmail.com>

release/observatory-agent.service

@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+[Unit]
+Description=Gamertan Observatory production agent
+After=network-online.target gamertan-observatory.service
+Wants=network-online.target
+PartOf=gamertan-observatory.service
+
+[Service]
+Type=simple
+User=observatory-agent
+Group=observatory-agent
+SupplementaryGroups=caddy eqlwiki gamertancom
+LoadCredential=agent.json:/etc/gamertan-observatory/agent.json
+LoadCredential=agent-credential.json:/etc/gamertan-observatory/agent-credential.json
+ExecStart=/opt/gamertan-observatory/current/observatory agent --systemd-credentials --config %d/agent.json --credential-file %d/agent-credential.json
+Restart=on-failure
+RestartSec=5s
+TimeoutStartSec=20s
+TimeoutStopSec=20s
+KillMode=mixed
+UMask=0077
+
+StateDirectory=gamertan-observatory-agent
+StateDirectoryMode=0700
+NoNewPrivileges=yes
+PrivateDevices=yes
+PrivateTmp=yes
+ProtectClock=yes
+ProtectControlGroups=yes
+ProtectHome=yes
+ProtectHostname=yes
+ProtectKernelLogs=yes
+ProtectKernelModules=yes
+ProtectKernelTunables=yes
+ProtectProc=invisible
+ProtectSystem=strict
+RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX
+RestrictNamespaces=yes
+RestrictRealtime=yes
+RestrictSUIDSGID=yes
+LockPersonality=yes
+MemoryDenyWriteExecute=yes
+SystemCallArchitectures=native
+CapabilityBoundingSet=
+AmbientCapabilities=
+ReadOnlyPaths=/proc /sys/fs/cgroup /var/log/caddy /var/log/eqlwiki /opt/gamertancom/deployment-events.jsonl /opt/sandwich-hime-site/deployment-events.jsonl /opt/gamertan-observatory/deployment-events.jsonl
+ReadWritePaths=/var/lib/gamertan-observatory-agent
+TasksMax=64
+MemoryMax=256M
+LimitNOFILE=1024
+
+[Install]
+WantedBy=multi-user.target