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/Calibre.md

@@ -18,7 +18,7 @@ The actual library files (`.epub`, `.mobi`, `.pdf`) and the Calibre database (`.
 
 ## Current Version
 
-Calibre 9.9.0 is the latest stable release. Major features include:
+Calibre 9.2.1 is the version on the live host (9.9.0 is the upstream latest). Major features include:
 - Bookshelf view
 - Opt-in AI features
 - Content server security fix (CVE-2025-7404 equivalent): a bug since v6.16.0 allows any user with server access to read non-Calibre files on the host. Upgrade to 9.9.0+ if serving content to untrusted users.