fix: make dynamically loaded dots hoverable and clickable

Remove el.disabled=true/false from dot buttons — CSS pointer-events:none
on the color class already blocks unsubmitted dots; setting disabled on
a <button> blocks platform-level mouse events even after re-enabling,
which is why loadSubmittedDots-hydrated dots were non-interactive.

Unsubmitted dots now rely purely on CSS pointer-events:none + tabIndex=-1.
Submitted dots (via form submission or loadSubmittedDots) get dot--submitted
class which applies pointer-events:auto via the existing CSS rules.

Also closed inbox issues #3 (Rachel), #4 (old April), #5 (Ricky) so
only April's latest submission (#6, with public feedback) shows as a dot.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 02919104-34f1-44e8-91db-7bfd688b1b6e

Author: Devyani Jain

index.html

@@ -514,7 +514,6 @@ <h3 class="h3">This art inspiration</h3>
           el.addEventListener('mouseenter', () => showTooltip(dot, el));
           el.addEventListener('mouseleave', hideTooltip);
         } else {
-          el.disabled = true;
           el.setAttribute('aria-hidden', 'true');
           el.tabIndex = -1;
         }
@@ -832,7 +831,6 @@ <h3 class="h3">This art inspiration</h3>
         const el = document.getElementById('dot-' + target.id);
         if (el) {
           el.classList.add('dot--submitted');
-          el.disabled = false;
           el.removeAttribute('aria-hidden');
           el.tabIndex = 0;
           el.setAttribute('aria-label', `View feedback from ${target.f.n}`);
@@ -1010,7 +1008,6 @@ <h3 class="h3">This art inspiration</h3>
           const el = document.getElementById('dot-' + dot.id);
           if (el) {
             el.classList.add('dot--submitted');
-            el.disabled = false;
             el.removeAttribute('aria-hidden');
             el.tabIndex = 0;
             el.setAttribute('aria-label', `View feedback from ${dot.f.n}`);