[fee25542] fix(a11y): bump tab-commits.tsx delete-commit button to 36px touch target

The per-commit unlink button used className="h-7 w-7" (28px), the one
sub-36px target the prior re-land commits (fda2ac0c/8e00303f/d8408c77/
34ea8fe1/e6bee7c8) didn't cover -- their content only fixed the header
grid-stack overflow in this file, not this button. Bumped to h-9 w-9
(36px) matching the Button component's own size="icon" default used
everywhere else in this fix series, and bumped the icon from h-3 w-3
to h-3.5 w-3.5 to stay visually proportional at the larger target.

panel-gate (lint + tsc --noEmit + vitest) is green.

panel/src/components/tasks/task-detail/tab-commits.tsx

@@ -291,9 +291,9 @@ export function TabCommits({ task }: TabCommitsProps) {
                         size="sm"
                         variant="ghost"
                         onClick={() => handleDelete(commit.hash)}
-                        className="h-7 w-7 p-0 opacity-0 group-hover:opacity-100 text-destructive"
+                        className="h-9 w-9 p-0 opacity-0 group-hover:opacity-100 text-destructive"
                       >
-                        <Trash2 className="h-3 w-3" />
+                        <Trash2 className="h-3.5 w-3.5" />
                       </Button>
                     </HelpTip>
                   </div>