Deploy Ollama LLM server on ringtail (#277)

## Summary
- Deploy Ollama as a new ArgoCD-managed service on ringtail's k3s cluster with GPU acceleration
- Declarative model management via `models.txt` + sidecar sync script (mirrors kiwix torrent pattern)
- Initial models: `qwen2.5:14b`, `deepseek-r1:14b`, `phi4:14b`, `gemma3:12b`
- hostPath PV on `/mnt/storage1/ollama` for fast local model storage (200Gi)
- Tailscale ingress at `ollama.ops.eblu.me` for API access from tailnet
- Enable GPU time-slicing (`replicas: 2`) on nvidia-device-plugin so Frigate and Ollama share the RTX 4080

## Deployment and Testing
- [ ] Deploy nvidia-device-plugin changes first: `argocd app sync nvidia-device-plugin`
- [ ] Verify GPU time-slicing: `kubectl describe node ringtail --context=k3s-ringtail` shows `nvidia.com/gpu: 2`
- [ ] Sync `apps` app with `--revision feature/ollama-ringtail`
- [ ] Set ollama app to branch: `argocd app set ollama --revision feature/ollama-ringtail && argocd app sync ollama`
- [ ] Verify model-sync sidecar pulls models: `kubectl logs -n ollama deploy/ollama -c model-sync --context=k3s-ringtail`
- [ ] Test API: `curl https://ollama.ops.eblu.me/api/tags`
- [ ] Test inference: `curl https://ollama.ops.eblu.me/api/generate -d '{"model":"qwen2.5:14b","prompt":"Hello"}'`
- [ ] Verify Frigate still works after GPU sharing change
- [ ] After merge: `argocd app set ollama --revision main && argocd app sync ollama`

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/277

ansible/roles/caddy/defaults/main.yml

@@ -85,6 +85,9 @@ caddy_services:
   - name: ntfy
     host: "ntfy.{{ caddy_domain }}"
     backend: "https://ntfy.tail8d86e.ts.net"
+  - name: ollama
+    host: "ollama.{{ caddy_domain }}"
+    backend: "https://ollama.tail8d86e.ts.net"
   - name: sifaka
     host: "nas.{{ caddy_domain }}"
     backend: "http://sifaka:5000"