UI: separate Updating filter for queued/active/paused downloads

Updating gets its own chip so Updatable shows only games the user could
still trigger. Anything mid-flight — queued, actively downloading,
paused with a partial on disk, or installing — moves to the new bucket.

Implemented in gameCategory(): downloading is true for both queued and
active jobs, so wartende Downloads (the user's words) show up in the
same list as the one actively transferring.

web/app.js

@@ -311,9 +311,12 @@ function renderGames() {
 
 // Mutually-exclusive bucket per game for the filter chips.
 function gameCategory(game) {
+  // In-flight work (queued, active, paused, installing) lives in its own
+  // bucket so Updatable shows only what the user could still trigger.
+  if (game.installing || game.downloading || game.resumable) return "updating";
   // checking is transient (version lookup still running); keep it visible under
   // Updatable rather than letting it fall out of every specific filter.
-  if (game.installing || game.downloading || game.status === "checking") return "updatable";
+  if (game.status === "checking") return "updatable";
   if (game.patch_title_match === false) return "blocked";
   if (game.status === "available" && isDownloadAllowed(game)) return "updatable";
   if (!sourcePolicy(game).allow_install && !sourcePolicy(game).allow_download) return "blocked";

web/index.html

@@ -110,6 +110,7 @@
             </div>
             <div class="segmented" role="group" aria-label="Filter">
               <button class="is-selected" data-filter="updatable" aria-pressed="true">Updatable</button>
+              <button data-filter="updating" aria-pressed="false">Updating</button>
               <button data-filter="uptodate" aria-pressed="false">Up to date</button>
               <button data-filter="needsfw" aria-pressed="false">Needs FW</button>
               <button data-filter="blocked" aria-pressed="false">Can't update</button>