Add WebDAV and backup docs to Seafile page

Seafile.md

@@ -36,6 +36,40 @@ Credentials stored in Vaultwarden AI collection:
 | `seafile-redis` | `redis` | Cache |
 | `seafile-caddy` | `lucaslorentz/caddy-docker-proxy` | Internal proxy (port 8077, unused) |
 
+## WebDAV
+
+WebDAV is enabled at `https://docs.alogins.net/seafdav/`. Each library appears as a folder.
+
+Mount on the host:
+```bash
+sudo mkdir -p /mnt/seafile
+sudo mount -t davfs https://docs.alogins.net/seafdav/ /mnt/seafile -o uid=1000,gid=1000
+# username: allogn@gmail.com, password: Seafile admin password
+```
+
+**Note:** add `127.0.0.1 docs.alogins.net` to `/etc/hosts` — the public IP is unreachable from the host itself (hairpin NAT).
+
+Enabled in `seafdav.conf` (inside container at `/shared/seafile/conf/`):
+```ini
+[WEBDAV]
+enabled = true
+port = 8080
+share_name = /seafdav
+```
+
+## Backup
+
+Script: `~/agap_git/seafile/backup.sh`
+Destination: `/mnt/backups/seafile/<timestamp>/`
+Schedule: every 3 days at 2:00 AM (root crontab)
+Retention: last 5 backups
+
+Backs up:
+- MySQL dumps of `ccnet_db`, `seafile_db`, `seahub_db` via `docker exec seafile-mysql mysqldump`
+- All seafile data via `rsync` (excludes mysql and caddy dirs)
+
+Zabbix monitoring: trapper item `seafile.backup.ts` (id `70369`) on host **AgapHost**. Trigger fires if no backup in 4 days.
+
 ## OnlyOffice Integration
 
 Online editing of `.docx`, `.xlsx`, `.pptx` via OnlyOffice Document Server.