release: 1.9.0: Per-application client IP allow-list and rate-limit overrides

Application sending controls: client IP allow-list for authorization, and level-2 rate limits that override the domain ceiling per application.
Added:
  - Per-application **client IP allow-list** on the domain page: when enabled,
  - SQLite migration `0009_application_auth_ips.sql` (moves legacy trusted IPs
Changed:
  - Application level-2 rate limit **overrides** the domain limit for that login
  - Domain export/import carries `auth_ip_restrict` / `auth_allowed_ips`; legacy
  - Panel help, Settings, and [guide.md](docs/guide.md) describe override semantics
  - [guide.md](docs/guide.md): full-backup section documents all four capture

Full detail: CHANGELOG.md (1.9.0).

deploy/docker-compose.yml

@@ -22,7 +22,7 @@
 
 services:
   selfpost:
-    image: ghcr.io/mixeme/selfpost:1.8.0
+    image: ghcr.io/mixeme/selfpost:1.9.0
     restart: unless-stopped
     environment:
       SELFPOST_HOSTNAME: "${SELFPOST_HOSTNAME:?set the mail/panel hostname, e.g. mail.example.com}"