perf(ui): remove dead runtime controllers and unused stylesheet families

Two orphaned controllers in the reactive runtime targeted markup nothing
emits any more: hydrateSidebarControllers looked for .wire-sidebar-shell and
friends, which the Sidebar rewrite replaced with BEM classes earlier today,
and hydrateDropdownControllers looked for [data-wrn-dropdown], which no
component or compiler output has ever produced.

ui.css loses the matching legacy sidebar rules, the wire-mega-menu family
left behind when the MegaMenu scaffold was replaced, and a set of
self-contained application-pattern families that nothing references.

Utility layers are deliberately kept even where an individual member is not
name-checked anywhere. wire-bg-primary is documented and tested while
wire-bg-secondary is not, but they are one public family and splitting them
would be incoherent.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

packages/ui/component-catalog.json

@@ -1,5 +1,7 @@
 {
-  "sourceDocuments": ["Screenshot-directed WRNexus UI catalog reset"],
+  "sourceDocuments": [
+    "Screenshot-directed WRNexus UI catalog reset"
+  ],
   "components": [
     {
       "name": "Accordion",