Add reference/tools/ category with Dagger, ArgoCD CLI, Ansible, and Pulumi cards (#178)

## Summary

- Create `docs/reference/tools/` with four reference cards: Dagger (build engine), ArgoCD CLI (deployment workflows), Ansible (config management), and Pulumi (DNS/Tailscale IaC)
- Move `ansible/roles.md` → `tools/ansible.md`, broadened with CLI patterns and dry-run usage
- Update `reference.md` index: add "Tools" section, remove old "Ansible" section
- Update `update-documentation.md` to reflect Dagger build process (workflow steps, manual build recipe, runner environment)
- Update `adopt-dagger-ci.md` plan to note how-to articles were handled via reference card + existing how-to updates
- Fix all broken `[[roles]]` wiki-links across 5 files → `[[ansible]]`

## Verification

- `docs-check-links` ✓ — no broken wiki-links
- `docs-check-index` ✓ — all docs referenced in category index
- `docs-check-filenames` ✓ — no duplicate filenames
- All pre-commit hooks pass

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/178

docs/explanation/why-gitops.md

@@ -46,7 +46,7 @@ BlumeOps uses layered GitOps:
 | Layer | Tool | What it manages |
 |-------|------|-----------------|
 | **Tailnet** | [[tailscale|Pulumi]] | ACLs, tags, DNS |
-| **Host config** | [[roles|Ansible]] | Services on [[indri]] |
+| **Host config** | [[ansible|Ansible]] | Services on [[indri]] |
 | **Kubernetes** | [[argocd|ArgoCD]] | Containerized workloads |
 
 Each layer has its own reconciliation loop:
@@ -68,4 +68,4 @@ But for BlumeOps, the trade-off is worth it. The infrastructure is complex enoug
 
 - [[architecture]] - How the pieces fit together
 - [[argocd]] - Kubernetes GitOps
-- [[roles|Ansible roles]] - Host configuration
+- [[ansible]] - Host configuration