🎨 Palette: Add aria-label and focus states to close icons

This commit enhances the accessibility of the application by adding missing `aria-label` attributes and keyboard focus visible states to icon-only "Close" buttons (`<X />`) in the `Dashboard.tsx` and `Analytics.tsx` components.

It ensures screen reader users understand the purpose of the buttons and keyboard navigators can clearly see when the buttons are focused.

Co-authored-by: Alesiobarquin <156465247+Alesiobarquin@users.noreply.github.com>

Author: google-labs-jules[bot]

src/components/Analytics.tsx

@@ -913,8 +913,9 @@ export const Analytics: React.FC = () => {
                 </div>
               </div>
               <button
+                aria-label="Close session details"
                 onClick={() => setViewingSession(null)}
-                className="w-10 h-10 flex items-center justify-center rounded-full hover:bg-zinc-800 text-zinc-400 hover:text-zinc-100 transition-colors"
+                className="w-10 h-10 flex items-center justify-center rounded-full hover:bg-zinc-800 text-zinc-400 hover:text-zinc-100 transition-colors focus-visible:ring-2 focus-visible:ring-emerald-500 outline-none"
               >
                 <X size={24} />
               </button>

src/components/Dashboard.tsx

@@ -568,7 +568,7 @@ export const Dashboard: React.FC = () => {
               <button onClick={() => setCatchUpPlan('CATCH_UP', missedDaysCount)} className="flex-1 sm:flex-none px-4 py-2 bg-amber-500 hover:bg-amber-400 text-amber-950 font-bold text-sm rounded-lg shadow-[0_0_15px_rgba(245,158,11,0.3)] transition-all flex items-center justify-center gap-2">
                 <Zap size={16} /> Catch Up Faster
               </button>
-              <button onClick={dismissCatchUpBanner} className="px-2 py-2 text-zinc-500 hover:text-zinc-300 rounded-lg hover:bg-zinc-800/50 transition-colors"><X size={18} /></button>
+              <button aria-label="Dismiss catch-up banner" onClick={dismissCatchUpBanner} className="px-2 py-2 text-zinc-500 hover:text-zinc-300 rounded-lg hover:bg-zinc-800/50 transition-colors focus-visible:ring-2 focus-visible:ring-emerald-500 outline-none"><X size={18} /></button>
             </div>
           </div>
         </div>