August 8 cleanup: modelortho inventory, hexclave rename, Mattermost decommission fix

- README: Add modelortho.com as hosted client under App3 services
- README: Remove Mattermost from backup pipeline table (was decommissioned)
- CHANGELOG: Document Hexclave → Stack Auth rename (2026-08-08)
- backup-plan: Fix fabricated '14 previously-unbacked' count → actual 6
- app1-backup.sh: Remove Mattermost backup section (decommissioned service)

README.md

@@ -73,6 +73,8 @@
     - debtreecoveryexperts.com, boxpilotlogistics.com, iamgmb.com
     - katiewattsdesign.com, vigilanttac.com, apextrackexperience.com
     - mainwp.itpropartner.com, voipsimplicity.com, my.voipsimplicity.com
+  - Hosted client sites (non-WordPress):
+    - modelortho.com — Anita Brown's orthodontic consulting (static placeholder, Hermes-built site pending)
   - Daily snapshots: 1 AM + 1 PM, 60-day retention, /opt/backup-restore/snapshots
 
 ### Core-BU (Warm Standby)
@@ -166,7 +168,7 @@ Direct API keys for all providers. Claude Sonnet 5 for primary quality, then dir
 | unifi-backup-sync | Daily 2 AM (Core) | s3://hermes-vps-backups/unifi-backups/ | UniFi configs (pulled from app2) |
 | hudu-backup | Daily 7 AM | s3://hermes-vps-backups/hudu/backups/ | Hudu volume dump |
 | gitea-backup | Daily 8 AM | s3://hermes-vps-backups/gitea/daily/ | Gitea repos |
-| app1-backup | Daily 2 AM | s3://hermes-vps-backups/app1/ | LiteLLM, n8n, OpenWebUI, MCP, Mattermost |
+| app1-backup | Daily 2 AM | s3://hermes-vps-backups/app1/ | LiteLLM, n8n, OpenWebUI, MCP configs |
 | app2-backup | Daily 2:30 AM | s3://hermes-vps-backups/app2/ | Traccar, Gitea, Hudu, UNMS, UniFi |
 | app3-backup | Daily 3 AM | s3://hermes-vps-backups/app3/ | CloudPanel, MySQL, WordPress |
 | wphost02-backup | Daily 5 AM | s3://hermes-vps-backups/wphost02-backup/ | Webapps + MySQL |