Fix Nextcloud DNS resolution and implement systemd cron for background jobs

- Enable IP forwarding in security playbook (net.ipv4.ip_forward = 1)
- Add podman network firewall rules to fix container DNS/HTTPS access
- Implement systemd timer for reliable Nextcloud background job execution
- Add database optimization tasks (indices, bigint conversion, mimetypes)
- Configure maintenance window (04:00 UTC) and phone region (NO)
- Add security headers (X-Robots-Tag, X-Permitted-Cross-Domain-Policies)
- Create Nextcloud removal playbook for clean uninstall
- Fix nftables interface matching (podman0 vs podman+)

Root cause: nftables FORWARD chain blocked container egress traffic
Solution: Explicit firewall rules for podman0 bridge interface

now-what.md

@@ -5,6 +5,7 @@
 
 - [ ] What gets served on jnss.me?
 - [ ] Backups
+- [x] Titan email provider support. For smtp access to hello@jnss.me
 
 - [ ] Vaultvarden
 
@@ -13,10 +14,12 @@
     - [ ] Settings
     - [ ] Contacts and calendars
     - [ ] Storage bucket integration?
+    - [x] SMTP setup for email sending
 
 - [x] Gitea
     - [x] SSH passthrough setup
     - [x] Figure out how to disable registration and local password
+    - [x] SMTP setup for email sending
 
 - [ ] Authentik Invitations for users?