Add event bindings and data-sx-emit processing

- adapter-dom.sx: detect :on-click/:on-submit etc. in render-dom-element
  — if attr starts with "on-" and value is callable, wire via dom-listen
- orchestration.sx: add process-emit-elements for data-sx-emit attrs
  — auto-dispatch custom events on click with optional JSON detail
- bootstrap_js.py: add processEmitElements RENAME
- Regenerate sx-ref.js with all changes
- Update reactive-islands status table

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sx/sx/reactive-islands.sx

@@ -115,8 +115,12 @@
               (td :class "px-3 py-2 font-mono text-xs text-stone-500" "boot.sx: sx-hydrate-islands, hydrate-island, dispose-island"))
             (tr :class "border-b border-stone-100"
               (td :class "px-3 py-2 text-stone-700" "Event bindings")
-              (td :class "px-3 py-2 text-amber-600 font-medium" "TODO")
-              (td :class "px-3 py-2 font-mono text-xs text-stone-500" ":on-click wiring"))
+              (td :class "px-3 py-2 text-green-700 font-medium" "Spec'd")
+              (td :class "px-3 py-2 font-mono text-xs text-stone-500" "adapter-dom.sx: :on-click → domListen"))
+            (tr :class "border-b border-stone-100"
+              (td :class "px-3 py-2 text-stone-700" "data-sx-emit processing")
+              (td :class "px-3 py-2 text-green-700 font-medium" "Spec'd")
+              (td :class "px-3 py-2 font-mono text-xs text-stone-500" "orchestration.sx: process-emit-elements"))
             (tr
               (td :class "px-3 py-2 text-stone-700" "Keyed list reconciliation")
               (td :class "px-3 py-2 text-amber-600 font-medium" "TODO")