Fix System page crash, retire "held" copy, and slim CLAUDE.md

- system.html crashed with a 500 whenever SABnzbd history loaded: the
  trend() macro compared the formatted "avg_speed" string (e.g. "900
  KB/s") against a number. Added a real numeric avg_speed_kbps field
  and pointed the macro at that instead.
- Replaced "held"/"not held" wording with "in library"/"not in
  library" on Home and Discover.
- Moved CLAUDE.md's Deployment/reverse-proxy and account-management
  sections into two on-demand skills (deploy-arr-summary,
  manage-accounts) so they only load when actually relevant, with a
  one-line pointer left in their place.
- Updated PRODUCT.md's restructure note now that meridian-marquee has
  merged to main.
- Dropped two stale/broken entries from settings.local.json's
  permission allowlist (a rule from a different machine/path, and one
  with a corrupted token).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NBw1QodG8ZMYHrGeQfqyDS

templates/system.html

@@ -120,7 +120,7 @@
         <div class="tt-fig-l">In queue</div>
       </div>
       <div class="tt-fig">
-        <div class="tt-dh tt-fig-v"><span id="sab-speed">{{ sabnzbd.speed | default('0') }}</span> {{ trend(sabnzbd.speed_kbps, sabnzbd.avg_speed) }}</div>
+        <div class="tt-dh tt-fig-v"><span id="sab-speed">{{ sabnzbd.speed | default('0') }}</span> {{ trend(sabnzbd.speed_kbps, sabnzbd.avg_speed_kbps) }}</div>
         <div class="tt-fig-l">Speed vs 7-day avg</div>
       </div>
       <div class="tt-fig">