Split RSS bots into their own category

New RSS_TYPES category with a /rss-bots page, sidebar entry, homepage tile, and an
explanation that RSS bots post a feed to a channel — share the channel link, not
the user. Remove rss from the Bots page (types table + create dropdown); the RSS
Bots page has a '+ New RSS Bot' button that only creates rss bots, with feed URL +
per hour/day/week fields shown directly (no bot-type select).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

manager/templates/home.html

@@ -40,6 +40,10 @@
     <span class="t-ico"><i class="fa-solid fa-robot"></i></span>
     <span class="t-title">Bots</span>
   </a>
+  <a class="tile" href="/rss-bots">
+    <span class="t-ico"><i class="fa-solid fa-rss"></i></span>
+    <span class="t-title">RSS Bots</span>
+  </a>
   <a class="tile" href="/businesses">
     <span class="t-ico"><i class="fa-solid fa-briefcase"></i></span>
     <span class="t-title">Business Groups</span>