docs: fact-check sweep, Jellyfin, *arr stack, and ROM scraping guides

Fact-check results:
- RomM 5.2.0: MariaDB+Redis now required (was SQLite), auth var renamed, 11 metadata providers
- Copyparty v1.20.19: 3 CVEs fixed, WOPI integration, docker editions documented
- Calibre-Web 0.6.27-ls397: version pinning, kepubify auto-config, CVE fixes
- Calibre 9.9.0: content server security fix noted

New documentation:
- docs/Dankserver/Jellyfin.md — full media server guide (compose, Caddy, GPU, metadata, clients)
- docs/Dankserver/ARR-Stack.md — automated download stack overview
- docs/Dankserver/RomM-Scraping.md — metadata providers, naming, cover art, emulator integration
- docs/Dankserver/sonarr.md, radarr.md, lidarr.md, readarr.md, prowlarr.md, qbittorrent.md
- docs/Dankserver/mariadb.md, redis.md — supporting services for RomM

Infrastructure updates:
- dankserver/compose.yaml: added mariadb, redis, jellyfin, *arr services
- dankserver/Caddyfile: added hostnames for all new services
- dankserver/.env.example: added all new environment variables
- docs/index.md: linked all new documentation pages

Tested: 52/52 tests pass.

docs/index.md

@@ -26,9 +26,20 @@ This repository tracks the container stacks for both hosts. Git is the single so
 ## Dankserver Services
 
 - [[RomM]] — retro game manager
+- [[RomM-Scraping]] — metadata providers, cover art, naming conventions
 - [[Copyparty]] — file sharing and streaming
+- [[Jellyfin]] — media server (movies, TV, music)
 - [[Calibre]] — e-book library engine
 - [[Calibre-Web]] — e-book web frontend
+- [[ARR-Stack]] — automated media download overview
+- [[sonarr]] — TV show management
+- [[radarr]] — movie management
+- [[lidarr]] — music management
+- [[readarr]] — ebook/audiobook management
+- [[prowlarr]] — indexer management
+- [[qbittorrent]] — torrent download client
+- [[mariadb]] — RomM database backend
+- [[redis]] — RomM cache/queue backend
 
 ## Dankclaw Services
 
@@ -59,6 +70,8 @@ This repository tracks the container stacks for both hosts. Git is the single so
 - [[ComfyUI ROCm and Vulkan]] — live-verified GPU path for ComfyUI on Strix Halo
 - [[Lemonade and sd.cpp]] — the ggml-family image-generation alternative
 - [[Backblaze Integration]] — off-site backup plan (future)
+- [[Jellyfin]] — media server research brief
+- [[ARR-Stack]] — automated download stack research brief
 
 ## See Also