feat(tracker): add aria labels and titles to icon buttons

Added `aria-label` and `title` attributes to the clear search button and
the AI send message button in TrackerLayout to improve accessibility and
user experience.

Co-authored-by: jmbish04 <26469722+jmbish04@users.noreply.github.com>

Author: google-labs-jules[bot]

src/frontend/src/components/project-dashboard/beta/TrackerLayout.tsx

@@ -232,6 +232,8 @@ export function TrackerLayout({ tasks, isLoading, onTaskUpdate, onTaskCreate, on
               <button
                 onClick={() => setSearchQuery('')}
                 className="absolute right-2 top-1/2 -translate-y-1/2 text-muted-foreground hover:text-foreground"
+                aria-label="Clear search"
+                title="Clear search"
               >
                 <X className="w-3.5 h-3.5" />
               </button>
@@ -302,7 +304,7 @@ export function TrackerLayout({ tasks, isLoading, onTaskUpdate, onTaskCreate, on
                     placeholder="Ask anything..."
                     className="h-8 text-sm"
                   />
-                  <Button size="sm" className="h-8 px-3" onClick={handleAiSend}>
+                  <Button size="sm" className="h-8 px-3" onClick={handleAiSend} aria-label="Send message" title="Send message">
                     <Send className="w-3.5 h-3.5" />
                   </Button>
                 </div>