Add Admin section to System: reclaim space from unwatched shows

Cross-references Sonarr's per-series disk usage against Tautulli's full
play history to surface the 10 largest shows nobody has ever watched,
excluding anything added in the last 6 months so new downloads aren't
flagged before they've had a chance to be watched. Delete removes the
series from Sonarr along with its episode files and folder, behind the
site's usual two-tap arm/confirm rather than a native dialog.

Also dedupes the never-wired /api/tautulli/never-watched endpoint onto
the same helper, and clears the Sonarr/Radarr list caches on delete so
a removed title doesn't linger in other cards until the TTL expires.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LPJxtE9tPURsaWDZ6rC4Dt

templates/system.html

@@ -161,4 +161,43 @@
     <div class="tt-field crit"><span>Indexers</span><span class="tt-field-meta">off air</span></div>
     {{ service_error('Prowlarr', prowlarr.error) }}
   {% endif %}
+
+  {#- ── Admin ─────────────────────────────────────────────────────
+      Shows Sonarr is holding, sized, that nobody has ever played in
+      Tautulli and that have sat untouched for longer than the
+      neglect window — largest first, since the point is reclaiming
+      space. Delete removes the series from Sonarr with its episode
+      files and folder; that's permanent, so it shares the site's
+      two-tap arming rather than a native confirm(). -#}
+  {% if admin_unwatched.status != 'ok' %}
+    <div class="tt-field crit"><span>Admin</span><span class="tt-field-meta">off air</span></div>
+    {{ service_error('Sonarr/Tautulli', admin_unwatched.error) }}
+  {% else %}
+    <div class="tt-field">
+      <span>Admin</span>
+      <span class="tt-field-meta" id="admin-meta">
+        {{ admin_unwatched.shows | length }} unwatched &middot; {{ admin_unwatched.total_display }} reclaimable
+      </span>
+    </div>
+    {% if admin_unwatched.shows %}
+    <div class="tt-rows" id="admin-rows">
+      {% for show in admin_unwatched.shows %}
+      <div class="tt-row" data-bytes="{{ show.size }}">
+        <span class="tt-row-name">{{ show.ep_count }} EP</span>
+        <span class="tt-row-body">
+          <span class="tt-row-title">{{ show.title }}</span>
+          {% if show.year %}<span class="tt-row-sub">{{ show.year }}</span>{% endif %}
+        </span>
+        <span class="tt-row-val">{{ show.size_display }}</span>
+        <span class="tt-row-acts">
+          <button class="tt-btn tt-btn-no tt-btn-sm" data-id="{{ show.sonarr_id }}"
+                  onclick="armDelete(this)" aria-label="Delete {{ show.title }}">Delete</button>
+        </span>
+      </div>
+      {% endfor %}
+    </div>
+    {% else %}
+      <p class="tt-empty" id="admin-empty">Nothing unwatched and older than {{ admin_unwatched.months }} months is taking up meaningful space.</p>
+    {% endif %}
+  {% endif %}
 {% endblock %}