Apply focus halo suppression to all PrimeVue buttons

The :focus:not(:focus-visible) rule was previously scoped only to
.icon-action-btn, so it only worked on the icon-only resend/trash
buttons in the workspace Members and project Collaborators tables.
Other invitation-related buttons (the labeled Resend pill on the
dashboard, the X on the dashboard, the labeled buttons in the
invitation sidebar) kept the lingering focus halo after a mouse click.

Move the rule out of .icon-action-btn and apply it globally to
.p-button. The :focus-visible exclusion still preserves the focus ring
for keyboard navigation, so accessibility is unaffected.

Author: harminius

web-app/packages/lib/src/assets/sass/themes/mm-theme-light/_extensions.scss

@@ -118,15 +118,16 @@ img {
   overflow-wrap: anywhere;
 }
 
+// Suppress the focus halo after a mouse click on any PrimeVue button while
+// keeping the ring for keyboard navigation (accessibility).
+.p-button:focus:not(:focus-visible) {
+  box-shadow: none;
+}
+
 // Icon-only action button used in list rows (e.g. resend / trash on invitation rows)
 .p-button.icon-action-btn {
   color: map-get($colors, 'forest');
 
-  // Suppress the focus halo after a mouse click
-  &:focus:not(:focus-visible) {
-    box-shadow: none;
-  }
-
   &:not(:disabled):hover {
     background: map-get($colors, 'light-green');
     color: map-get($colors, 'forest');