Bump remaining apps: major version slots and infrastructure

New version slots (major version jumps):
- gitea: 1.24.3 -> 28.2.0 (slot 1 -> 28)
- ghost: 5.130.6 -> 6.72.0 (slot 5 -> 6)
- formbricks: 3.6.0 -> 6.1.0 (slot 3 -> 6)
- mattermost: 10.8.1 -> 12.0.1 (slot 10 -> 12)
- zulip: 9.4 -> 12.3 (slot 9 -> 12)
- immich: 1.135.3 -> 3.3.5 (slot 1 -> 3)
- openproject: 16.1.1 -> 17.9.3 (slot 16 -> 17)
- listmonk: 5.0.3 -> 6.1.0 (slot 5 -> 6)
- discourse: 3.5.3 -> 2026.10.0 (slot 3 -> 2026, calver)

Same-slot large bumps:
- vllm: 0.9.2 -> 0.32.0
- longhorn: v1.8.1 -> v1.13.0

Infrastructure:
- cert-manager: v1.17.2 -> v1.21.2
- coredns: v1.12.0 -> v1.14.7
- externaldns: v0.13.4 -> v0.23.0
- metallb: v0.15.0 -> v0.16.1
- mysql: 9.1.0 -> 9.7.4
- node-feature-discovery: v0.17.3 -> v0.20.1
- nvidia-device-plugin: v0.17.1 -> v0.20.1

zulip/versions/12/README.md

@@ -0,0 +1,42 @@
+# Zulip
+
+Zulip is an open-source team messaging platform with a unique topic-based threading model.
+
+## Dependencies
+
+- **SMTP** - For sending invitations and notifications
+- **Redis** - Used for caching and real-time event queuing
+
+Zulip bundles its own **PostgreSQL**, **RabbitMQ**, and **Memcached** instances — these are deployed alongside the main Zulip pod and are not shared with other apps.
+
+## Configuration
+
+Key settings in `config.yaml`:
+
+- **domain** - Where Zulip will be accessible
+- **adminEmail** - Admin account email (defaults to your operator email)
+- **smtp** - Email settings inherited from your Wild Cloud SMTP service
+
+## First-Time Setup
+
+1. Add and deploy the app:
+   ```bash
+   wild app add zulip
+   wild app deploy zulip
+   ```
+
+2. **First start takes 5–10 minutes** as Zulip runs hundreds of Django database migrations. Wait until the pod shows `1/1 Running`.
+
+3. The admin account is pre-configured with the `adminEmail` and `adminPassword` from `secrets.yaml`. Visit the app URL and log in.
+
+4. Complete the realm (organization) setup wizard on first login.
+
+## Inviting Users
+
+Send invitation emails from **Settings → Organization → Invitations**, or use pre-generated invite links.
+
+## Notes
+
+- The `secretKey`, `postgresPassword`, and `rabbitmqPassword` are all auto-generated in `secrets.yaml`
+- Zulip's topic-based threading keeps conversations organized — each stream (channel) has multiple topics
+- Mobile and desktop apps are available and connect to self-hosted instances