Auto-deploy docs from build workflow (#93)

## Summary
- Add `uv` and `argocd` CLI to forgejo-runner container image
- Add `workflow-bot` ArgoCD account with sync permissions (declarative via kustomize patches)
- Add `ARGOCD_AUTH_TOKEN` to forgejo-runner external secret for workflow auth
- Update build workflow to auto-deploy docs after release:
  - Update configmap with new release URL
  - Commit changelog and configmap changes
  - Sync docs app via ArgoCD

## Deployment and Testing
Manual steps required before this can work:
1. [ ] Build and push new forgejo-runner image (v2.4.0)
2. [ ] Sync argocd app to create workflow-bot account
3. [ ] Generate token: `argocd account generate-token --account workflow-bot`
4. [ ] Store token in 1Password under "Forgejo Secrets" with field `argocd_token`
5. [ ] Sync forgejo-runner app to pick up new external secret
6. [ ] Update forgejo-runner deployment to use new image version
7. [ ] Test by running workflow manually

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

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/93

docs/changelog.d/feature/auto-deploy-docs.feature.md

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+Build workflow now automatically deploys docs after release by updating the configmap and syncing ArgoCD