Enforce unique doc filenames and simple wiki-links (#109)

## Summary
- Rename section index files to match their titles (tutorials.md, reference.md, how-to.md, explanation.md) so all filenames are unique
- Convert all ~47 path-based wiki-links to simple filename format across 15 files
- Update doc-filenames task to no longer skip index.md files
- Update doc-links task to reject path-based links containing '/'

This ensures all wiki-links work correctly in obsidian.nvim by making links resolvable by filename alone.

## Testing
- `mise run doc-filenames` - all unique
- `mise run doc-links` - no broken or path-based links
- `mise run doc-titles` - no duplicates

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/109

docs/reference/reference.md

@@ -0,0 +1,78 @@
+---
+title: reference
+tags:
+  - reference
+---
+
+# Reference
+
+Technical specifications, inventories, and configuration details for BlumeOps infrastructure.
+
+## Services
+
+Individual service reference cards with URLs and configuration details.
+
+| Service | Description | Location |
+|---------|-------------|----------|
+| [[alloy|Alloy]] | Observability collector (metrics & logs) | indri + k8s |
+| [[argocd]] | GitOps continuous delivery | k8s |
+| [[borgmatic]] | Backup system | indri |
+| [[caddy]] | Reverse proxy & TLS termination | indri |
+| [[1password]] | Secrets management | cloud + k8s |
+| [[forgejo]] | Git forge & CI/CD | indri |
+| [[grafana]] | Dashboards & visualization | k8s |
+| [[immich]] | Photo management | k8s |
+| [[jellyfin]] | Media server | indri |
+| [[kiwix]] | Offline Wikipedia & ZIM archives | k8s |
+| [[loki]] | Log aggregation | k8s |
+| [[miniflux]] | RSS feed reader | k8s |
+| [[navidrome]] | Music streaming | k8s |
+| [[postgresql]] | Database cluster | k8s |
+| [[prometheus]] | Metrics collection | k8s |
+| [[teslamate]] | Tesla data logger | k8s |
+| [[transmission]] | BitTorrent daemon | k8s |
+| [[zot]] | Container registry | indri |
+| [[devpi]] | PyPI caching proxy | k8s |
+| [[docs]] | Documentation site (Quartz) | k8s |
+| [[automounter]] | SMB share automounter | indri |
+
+## Infrastructure
+
+Host inventory and network configuration.
+
+- [[hosts|Hosts]] - Device inventory
+- [[indri]] - Primary server
+- [[gilbert]] - Development workstation
+- [[tailscale]] - ACLs, groups, tags
+- [[routing|Routing]] - DNS domains, port mappings
+
+## Kubernetes
+
+Cluster configuration and application registry.
+
+- [[cluster|Cluster]] - Minikube specs, storage, networking
+- [[apps|Apps]] - ArgoCD application registry
+- [[tailscale-operator]] - Tailscale ingress for k8s services
+- [[external-secrets]] - Secrets management
+
+## Ansible
+
+Configuration management for [[indri]]-hosted services.
+
+- [[roles]] - Available ansible roles
+
+## Storage
+
+Network storage and backup configuration.
+
+- [[sifaka|Sifaka]] - Synology NAS configuration
+- [[postgresql-storage]] - Database cluster
+- [[backups|Backups]] - Backup policy and schedule
+
+## Operations
+
+Operational concerns and their components.
+
+- [[observability]] - Metrics, logs, dashboards
+- [[backup]] - Data protection
+- [[disaster-recovery]] - Recovery procedures (TBD)