Update all docs titles to human-readable (#117)

## Summary
- Updated frontmatter `title:` in all 63 doc cards from slug-case to human-readable (e.g. `borgmatic` → `Borgmatic`, `ai-assistance-guide` → `AI Assistance Guide`)
- Titles now closely match file stems so `[[wiki-links]]` render naturally without alternate anchor text
- Corrected titles that diverged from stems (e.g. `host-inventory` → `Hosts`, `grafana-alloy` → `Alloy`, `argocd-applications` → `Apps`)
- Deleted `title-test-alpha.md` and `title-test-beta.md` test cards and removed their reference index entry

## Deployment and Testing
- [x] `docs-check-links` passes — all wiki-links valid
- [x] `docs-check-index` passes
- [x] `docs-check-filenames` passes
- [ ] Verify titles render correctly on docs site after deploy

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/117

docs/reference/infrastructure/gandi.md

@@ -1,5 +1,5 @@
 ---
-title: gandi
+title: Gandi
 tags:
   - infrastructure
   - networking

docs/reference/infrastructure/gilbert.md

@@ -1,5 +1,5 @@
 ---
-title: gilbert
+title: Gilbert
 tags:
   - infrastructure
   - host

docs/reference/infrastructure/hosts.md

@@ -1,5 +1,5 @@
 ---
-title: host-inventory
+title: Hosts
 tags:
   - infrastructure
 ---

docs/reference/infrastructure/indri.md

@@ -1,5 +1,5 @@
 ---
-title: indri
+title: Indri
 tags:
   - infrastructure
   - host

docs/reference/infrastructure/routing.md

@@ -1,5 +1,5 @@
 ---
-title: service-routing
+title: Routing
 tags:
   - infrastructure
   - networking

docs/reference/infrastructure/tailscale.md

@@ -1,5 +1,5 @@
 ---
-title: tailscale
+title: Tailscale
 tags:
   - infrastructure
   - networking

docs/reference/infrastructure/title-test-alpha.md

@@ -1,13 +0,0 @@
----
-title: Title Test Card
-tags:
-  - infrastructure
-  - test
----
-
-# Title Test Card (Alpha)
-
-This card tests that duplicate frontmatter titles don't break wiki-link resolution.
-This card and [[title-test-beta]] share the same `title:` frontmatter value.
-
-If you can read both cards and the links work, the test passes.

docs/reference/infrastructure/title-test-beta.md

@@ -1,13 +0,0 @@
----
-title: Title Test Card
-tags:
-  - infrastructure
-  - test
----
-
-# Title Test Card (Beta)
-
-This card tests that duplicate frontmatter titles don't break wiki-link resolution.
-This card and [[title-test-alpha]] share the same `title:` frontmatter value.
-
-If you can read both cards and the links work, the test passes.