feat(dashboard): add Tools & Apps page with liveness probes

New page at /tools listing all connected applications grouped by
category: Local Services (State Hub API, KeePassXC, pgAdmin, ops-bridge),
Source Control (Gitea), Identity/Auth (KeyCape, Authelia, privacyIDEA,
LLDAP), and Dev Tooling (Claude Code, uv). Local services show live
green/red/grey status dots via no-cors fetch probes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dashboard/observablehq.config.js

@@ -27,6 +27,7 @@ export default {
     { name: "Progress",      path: "/progress" },
     { name: "Services (TPSC)", path: "/tpsc" },
     { name: "Todo",          path: "/todo" },
+    { name: "Tools & Apps",  path: "/tools" },
     // ── Sections (alphabetical) ───────────────────────────────────────────────
     {
       name: "Policies",