Persist Redis (AOF+vol), read config from mounted secrets.js, add backup/restore docs (#34)

Lossless upgrades + config story for the all-in-one image.

Redis persistence (Part A):
- Replace in-memory `--save "" --appendonly no` with AOF + RDB persisted to /data
  (--appendonly yes, periodic saves, --dbfilename dump.rdb). OAuth clients,
  tokens, and other model-redis state now survive container recreation.
- Add the `sso-data` named volume -> /data in docker-compose.yml.

Config from ./config/sso-secrets.js (Part B):
- docker-entrypoint.sh: when /config/sso-secrets.js is mounted, symlink it to
  /app/conf/secrets.js and read the server-side LDAP vars (base DN, admin pass,
  org, domain, cert CN, JWT) from the file via one `node` call (base64-decoded,
  no eval/quoting hazards). No app_* env is exported in this mode, so the file
  is authoritative (@simpleworkjs/conf precedence: base < env < secrets.js <
  app_* env). Falls back to the existing LDAP_* env-var mode when the file is
  absent (standalone/bare-metal still works).
- docker-compose.yml: trim `environment:` to NODE_ENV/NODE_PORT only and add
  `./config:/config:ro`. Removing the app_* env is required — any leftover
  app_* would silently override secrets.js.
- secrets.js.example: add orchestrator-only `stack`, `bootstrap`, and
  `serviceAccountPass` keys (ignored by the app; read by the entrypoint, the
  theta-env bootstrap, and setup.sh).

Backup/restore docs:
- Full "Backups and restore" runbook in DEPLOYMENT.md (what lives where,
  manual backup, full / Redis-only / LDAP-only restore, AOF-vs-RDB note,
  upgrades). Restore uses slapadd -f (static slapd.conf), and RDB restore
  requires deleting the AOF first (AOF wins on startup).
- Pointers in docs/deployment.md and docs/ldap.md; update the Docker Setup
  section for the new ./config/ approach (env vars now advanced/optional).

Co-authored-by: Claude <noreply@anthropic.com>

docs/ldap.md

@@ -123,14 +123,33 @@ idempotently against a running slapd (auto-detects the database holding your
 base DN, and verifies `pwdAccountLockedTime` is live — the attribute the app's
 active/inactive toggle depends on).
 
-## Backups
+## Backups and restore
+
+**Backup** (while slapd is running):
 
 ```bash
 docker compose exec sso-manager slapcat -f /etc/openldap/slapd.conf \
   -b "dc=yourdomain,dc=com" > ldap-backup-$(date +%F).ldif
 ```
 
-Restorable with `ldapadd`/`ldapmodify` against a fresh instance.
+Store the `.ldif` off the host — it contains every user's password hash.
+
+**Restore** into a stopped directory. The SSO image uses a static `slapd.conf`
+(slapd starts with `-f`, not cn=config `-F`), so restore uses `slapadd -f`:
+
+```bash
+docker compose stop sso-manager
+docker compose run --rm --no-deps --entrypoint sh sso-manager -c \
+  'rm -f /var/lib/ldap/* && slapadd -f /etc/openldap/slapd.conf -l /dev/stdin' \
+  < ldap-backup-<date>.ldif
+docker compose start sso-manager
+```
+
+Verify: `docker compose exec sso-manager ldapsearch -x -b "dc=yourdomain,dc=com"`.
+
+Redis state (OAuth clients, tokens) and `./config/` secrets are backed up
+separately — see the *Backups and restore* section of `DEPLOYMENT.md` for the
+full (LDAP + Redis + secrets) runbook.
 
 ## Troubleshooting