feat(member): bring the overview table up to WCAG 2.2 AA

assets/css/app.css

@@ -957,16 +957,3 @@
   margin-bottom: 0;
 }
 
-/*
- * Sort-header tooltips must render on top of the pinned checkbox column's
- * horizontal-scroll fade (::after on .sticky-first-col-th). The hovered/focused
- * header th is already lifted above the checkbox th (hover/focus-within:z-50),
- * so the whole tooltip wins the stacking; this rule additionally keeps the
- * daisyUI tooltip bubble's own pseudo-elements above the fade overlay. Scoped
- * to the member overview header so no unrelated tooltip is affected.
- */
-#members-keyboard thead .tooltip::before,
-#members-keyboard thead .tooltip::after {
-  z-index: 60;
-}
-

assets/js/app.js

@@ -36,6 +36,22 @@ function getBrowserTimezone() {
 // Hooks for LiveView components
 let Hooks = {}
 
+// IndeterminateCheckbox: the `indeterminate` state of a checkbox is a JS
+// property, not an HTML attribute, so it cannot be set from the server render.
+// Mirror it from the data-indeterminate attribute on mount and every update
+// (e.g. select-all reflecting a partial selection — WCAG select-all semantics).
+Hooks.IndeterminateCheckbox = {
+  updateIndeterminate() {
+    this.el.indeterminate = this.el.dataset.indeterminate === "true"
+  },
+  mounted() {
+    this.updateIndeterminate()
+  },
+  updated() {
+    this.updateIndeterminate()
+  }
+}
+
 // CopyToClipboard hook: Copies text to clipboard when triggered by server event
 Hooks.CopyToClipboard = {
   mounted() {