feat(a11y): make the 'unselect' action invert the selection

Replace the select-all/unselect-all toggle with three distinct actions:
Select all (visible), Invert (flip each visible violation's selected state),
and Clear selection.

Author: antfubot

plugins/a11y/src/spa/app.tsx

@@ -148,16 +148,27 @@ export function App() {
     return keys.length > 0 && keys.every(k => selected().has(k))
   })
 
-  // Select all / unselect all — toggles the whole visible set at once.
-  function toggleSelectAll() {
+  // Select every visible (filtered) violation.
+  function selectAll() {
+    const keys = visibleKeys()
+    if (keys.length === 0)
+      return
+    setSelected((prev) => {
+      const next = new Set(prev)
+      for (const k of keys)
+        next.add(k)
+      return next
+    })
+  }
+  // Invert the selection across the visible violations (selected ↔ unselected).
+  function invertSelection() {
     const keys = visibleKeys()
     if (keys.length === 0)
       return
-    const allSel = keys.every(k => selected().has(k))
     setSelected((prev) => {
       const next = new Set(prev)
       for (const k of keys) {
-        if (allSel)
+        if (next.has(k))
           next.delete(k)
         else
           next.add(k)
@@ -362,7 +373,8 @@ export function App() {
               routeCount={routes().length}
               selectedCount={selectedItems().length}
               allSelected={allVisibleSelected()}
-              onToggleSelectAll={toggleSelectAll}
+              onSelectAll={selectAll}
+              onInvertSelection={invertSelection}
               onClearSelection={clearSelection}
               autoScan={autoScan()}
               onToggleAutoScan={setAutoScan}

plugins/a11y/src/spa/components/SummaryBar.stories.tsx

@@ -23,7 +23,8 @@ const base = {
   routeCount: 3,
   selectedCount: 0,
   allSelected: false,
-  onToggleSelectAll: noop,
+  onSelectAll: noop,
+  onInvertSelection: noop,
   onClearSelection: noop,
   autoScan: true,
   onToggleAutoScan: noop,

plugins/a11y/src/spa/components/SummaryBar.tsx

@@ -15,8 +15,10 @@ interface SummaryBarProps {
   selectedCount: number
   /** Whether every currently-visible violation is selected. */
   allSelected: boolean
-  /** Select all visible violations, or unselect them when all are selected. */
-  onToggleSelectAll: () => void
+  /** Select all visible violations. */
+  onSelectAll: () => void
+  /** Invert the selection across the visible violations. */
+  onInvertSelection: () => void
   /** Clear the entire selection (including any hidden by the filter). */
   onClearSelection: () => void
   autoScan: boolean
@@ -51,11 +53,22 @@ export function SummaryBar(props: SummaryBarProps) {
         <button
           type="button"
           class={ACTION}
-          onClick={() => props.onToggleSelectAll()}
-          title={props.allSelected ? 'Unselect all visible violations' : 'Select all visible violations'}
+          onClick={() => props.onSelectAll()}
+          disabled={props.allSelected}
+          title="Select all visible violations"
         >
-          <span aria-hidden class={`shrink-0 ${props.allSelected ? 'i-ph-check-square-duotone' : 'i-ph-square-duotone'}`} />
-          {props.allSelected ? 'Unselect all' : 'Select all'}
+          <span aria-hidden class="i-ph-check-square-duotone shrink-0" />
+          Select all
+        </button>
+
+        <button
+          type="button"
+          class={ACTION}
+          onClick={() => props.onInvertSelection()}
+          title="Invert the selection across the visible violations"
+        >
+          <span aria-hidden class="i-ph-selection-inverse-duotone shrink-0" />
+          Invert
         </button>
 
         <Show when={props.selectedCount > 0}>