refactor: improve PR display and interaction in worktree components

- Updated WorktreeActionsDropdown to use DropdownMenuItem for better interaction with PR links.
- Enhanced WorktreeTab to include hover and active states for buttons, and improved accessibility with updated titles and aria-labels.
- Ensured PR URLs are safely opened only if they exist, enhancing user experience and preventing errors.

apps/ui/src/components/views/board-view/worktree-panel/components/worktree-actions-dropdown.tsx

@@ -185,13 +185,18 @@ export function WorktreeActionsDropdown({
         {/* Show PR info and Address Comments button if PR exists */}
         {!worktree.isMain && hasPR && worktree.pr && (
           <>
-            <DropdownMenuLabel className="text-xs flex items-center gap-2">
+            <DropdownMenuItem
-              <GitPullRequest className="w-3 h-3" />
+              onClick={() => {
+                window.open(worktree.pr!.url, "_blank");
+              }}
+              className="text-xs"
+            >
+              <GitPullRequest className="w-3 h-3 mr-2" />
               PR #{worktree.pr.number}
-              <span className="ml-auto text-[10px] bg-green-500/20 text-green-600 px-1.5 py-0.5 rounded">
+              <span className="ml-auto text-[10px] bg-green-500/20 text-green-600 px-1.5 py-0.5 rounded uppercase">
                 {worktree.pr.state}
               </span>
-            </DropdownMenuLabel>
+            </DropdownMenuItem>
             <DropdownMenuItem
               onClick={() => {
                 // Convert stored PR info to the full PRInfo format for the handler

apps/ui/src/components/views/board-view/worktree-panel/components/worktree-tab.tsx

@@ -157,7 +157,7 @@ export function WorktreeTab({
         className={cn(
           "ml-1.5 inline-flex items-center gap-1 rounded-full border px-1.5 py-0.5 text-[10px] font-medium transition-colors",
           "focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-1 focus:ring-offset-background",
-          "appearance-none cursor-pointer", // Reset button appearance but keep cursor
+          "appearance-none cursor-pointer hover:opacity-80 active:opacity-70", // Reset button appearance but keep cursor, add hover/active states
           prStateClasses
         )}
         style={{
@@ -165,24 +165,28 @@ export function WorktreeTab({
           backgroundImage: "none",
           boxShadow: "none",
         }}
-        title={prLabel}
+        title={`${prLabel} - Click to open`}
-        aria-label={prLabel}
+        aria-label={`${prLabel} - Click to open pull request`}
         onClick={(e) => {
           e.stopPropagation(); // Prevent triggering worktree selection
-          window.open(worktree.pr.url, "_blank", "noopener,noreferrer");
+          if (worktree.pr?.url) {
+            window.open(worktree.pr.url, "_blank", "noopener,noreferrer");
+          }
         }}
         onKeyDown={(e) => {
           // Prevent event from bubbling to parent button
           e.stopPropagation();
           if (e.key === "Enter" || e.key === " ") {
             e.preventDefault();
-            window.open(worktree.pr.url, "_blank", "noopener,noreferrer");
+            if (worktree.pr?.url) {
+              window.open(worktree.pr.url, "_blank", "noopener,noreferrer");
+            }
           }
         }}
       >
         <GitPullRequest className={cn("w-3 h-3", getStatusColorClass())} aria-hidden="true" />
         <span aria-hidden="true" className={isSelected ? "text-foreground font-semibold" : ""}>
-          #{worktree.pr.number}
+          PR #{worktree.pr.number}
         </span>
         <span className={cn("capitalize", getStatusColorClass())} aria-hidden="true">
           {prState}