Decommission JobSync service (#308)

## Summary

- Remove all JobSync infrastructure: ArgoCD app, k8s manifests, container build (nix), Caddy reverse proxy entry, Homepage dashboard entry, service-versions tracking, and all documentation
- Runtime teardown already completed: ArgoCD app cascade-deleted (removes deployment, PVC, service, ingress, external-secret), forge mirror deleted, 1Password item archived, local clone removed

## Motivation

Replacing JobSync with a datasette-based job tracking pipeline driven by mise tasks and a Claude agent frontend. JobSync's Next.js server actions don't expose a useful API for automation.

## Remaining manual steps after merge

- Provision Caddy to remove the stale proxy route: `mise run provision-indri -- --tags caddy`
- Sync Homepage: `argocd app sync homepage`
- Verify namespace cleanup on ringtail: `kubectl get ns jobsync --context=k3s-ringtail` (should be gone)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Reviewed-on: #308

ansible/roles/caddy/defaults/main.yml

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