style(type): raise the too-small toolbar and filter text toward the view-switcher size

The view-switcher's 16px reads comfortably; the toolbar and filter controls sat at 12px. Bring
the marked controls up to match, and lift the general scale on the shared filter surfaces.

- Toolbar (feed + channel + Plex, via the shared components): FilterSelect and SortControl trigger
  pills text-xs → text-base (16px, the view-switcher size); the result count → text-sm; the
  active-filter chips → text-sm with the "FILTERED BY" label text-2xs → text-xs.
- Filterbar: the Combobox picker input → text-base (matching the toolbar pills) + its chips → text-sm;
  the panel/widget headers (SidePanel collapsed-rail + panel title, PanelGroup widget titles) up one step.

Channel info and the manager tables were already at 14–16px (readable), so they were left as-is.

frontend/src/components/SortControl.tsx

@@ -68,7 +68,7 @@ export default function SortControl({
         ref={pop.refs.setReference}
         {...pop.getReferenceProps()}
         aria-label={label}
-        className={`glass-card glass-hover inline-flex items-center gap-1.5 rounded-full border px-3 py-1 text-xs transition ${
+        className={`glass-card glass-hover inline-flex items-center gap-1.5 rounded-full border px-3 py-1 text-base transition ${
           open ? "border-accent" : "border-border"
         }`}
       >