Keep a feed, an OPML or a Patreon creator out of All Subscriptions (#288)

A switch in the feed's settings, In All Subscriptions, on its
subscription as hide_from_all. All Subscriptions' list and count leave
out a feed hidden on its own or through the OPML it is in, and the page's
unread count does the same. Signals read every feed as before, and
Currently Listening, which is All Subscriptions' in-progress filter, keeps
an episode under way whatever the feed's setting.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/types.ts

@@ -37,6 +37,8 @@ interface Feed {
   pinned: boolean;
   /** From an OPML, and yours to keep should it drop the feed (#280). */
   kept: boolean;
+  /** Left out of All Subscriptions by its own setting; a show is also when its OPML is (#288). */
+  hide_from_all: boolean;
   private: boolean;
   private_by_address: boolean;
 }