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/radarr.md

@@ -8,7 +8,7 @@ Radarr manages movies in the *arr stack on Dankserver. It automatically searches
 
 | Item | Value |
 |------|-------|
-| Image | `lscr.io/linuxserver/radarr:latest` (v4 stable) |
+| Image | `lscr.io/linuxserver/radarr:latest` (v6 stable) |
 | Port | 7878 (host) → 7878 (container) |
 | Min RAM | 512 MB |
 | Metadata | TMDB / TheMovieDB API |
@@ -44,7 +44,7 @@ radarr:
 
 ## Gotchas
 
-- Radarr v4 is the current stable. `:latest` points to v4, not v5.
+- Radarr v6 is the current stable (v6.3.x as of 2026-08). `:latest` points to the current release.
 - Movie renaming produces `Title (Year)` format. Jellyfin scanner handles this.
 - File permissions: qBittorrent downloads as PUID; arr apps must read/move files.