wiki: add Plex 4K codec guide and mdadm USB recovery; update yt-dlp, indexes

New articles:
- 04-streaming/plex/plex-4k-codec-compatibility.md
- 05-troubleshooting/storage/mdadm-usb-hub-disconnect-recovery.md

Updated:
- yt-dlp.md: Plex section and config reflect new HEVC auto-convert workflow
- SUMMARY.md, index.md, README.md, section indexes: 39 → 41 articles
- MajorWiki-Deploy-Status.md: count + date

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

SUMMARY.md

@@ -30,6 +30,7 @@
     * [yt-dlp: Video Downloading](03-opensource/media-creative/yt-dlp.md)
 * [Streaming & Podcasting](04-streaming/index.md)
     * [OBS Studio Setup & Encoding](04-streaming/obs/obs-studio-setup-encoding.md)
+    * [Plex 4K Codec Compatibility (Apple TV)](04-streaming/plex/plex-4k-codec-compatibility.md)
 * [Troubleshooting](05-troubleshooting/index.md)
     * [Apache Outage: Fail2ban Self-Ban + Missing iptables Rules](05-troubleshooting/networking/fail2ban-self-ban-apache-outage.md)
     * [Mail Client Stops Receiving: Fail2ban IMAP Self-Ban](05-troubleshooting/networking/fail2ban-imap-self-ban-mail-client.md)
@@ -42,3 +43,4 @@
     * [MajorWiki Setup & Publishing Pipeline](05-troubleshooting/majwiki-setup-and-pipeline.md)
     * [Gitea Actions Runner: Boot Race Condition Fix](05-troubleshooting/gitea-runner-boot-race-network-target.md)
     * [SELinux: Fixing Dovecot Mail Spool Context (/var/vmail)](05-troubleshooting/selinux-dovecot-vmail-context.md)
+    * [mdadm RAID Recovery After USB Hub Disconnect](05-troubleshooting/storage/mdadm-usb-hub-disconnect-recovery.md)