Doc audit: fix all broken links + correct stale facts across the KB

Fanned out 5 read-only doc-auditor subagents (one per service group) that
fact-checked the knowledge base against the live system + repo config,
researched official setup docs online, and verified progress. Applied:
- All 34 broken links fixed (real pages / external URLs / correct relative
  paths); 0 broken links remain. No .AGENTTRASH links (the 4 mentions are
  accurate descriptive text, not links).
- Fact-check fixes: Readarr retired (May 2026), Radarr v4->v6, Calibre
  9.2.1 live, Calibre-Web 0.6.25 live, Copyparty v1.20.21, LLM index
  ncmoe 38 + 786432 ctx, frank-default-small active (not frank-pp-worker),
  Hermes/SearXNG/Grafana hostnames, Loki/Alloy local images, Observability
  diagram (Promtail->Alloy), VLLM retired note, DFlash status, benchmark
  live-drift notes, Homepage test count 116.

docs/Dankserver/ARR-Stack.md

@@ -365,5 +365,5 @@ Use Copyparty for curated file collections. Use *arr for automatic downloads. Us
 - [[Jellyfin]] — media server that consumes *arr downloads
 - [[Copyparty]] — alternative file viewer
 - [[Calibre-Web]] — manual ebook management (Readarr auto-downloads into the same library)
-- [[Sonarr Wiki]] — https://wiki.servarr.com/sonarr
-- [[Radarr Wiki]] — https://wiki.servarr.com/radarr
+- [Sonarr Wiki](https://wiki.servarr.com/sonarr)
+- [Radarr Wiki](https://wiki.servarr.com/radarr)