feat(frontend): My Reviews queue, duplicate-test badge, tactic order, legend + tooltip fixes

- TestsPage gains a "My Reviews" toggle for red_lead/blue_lead, separate
  from "My Tasks" — filters by reviewer_id at the red_review/blue_review
  gate instead of the unrelated in_review validation stage
- Test Catalog cards now warn when a technique already has existing
  tests, using the backend's new existing_test_count
- ExecutiveDashboardPage drops its duplicate client-side tactic-order
  sort now that the backend returns canonical order; time-range filter
  now notes which sections it actually scopes
- HeatmapLegend adds the missing review_required swatch (as an overlay
  indicator, matching how it's actually rendered on cells) and hover
  tooltips reusing StatusBadge's copy instead of being unexplained
  static color chips
- Fix a real React key bug in ControlsTable: rows were grouped in a
  keyless shorthand fragment, which can misreconcile when the table is
  filtered/sorted; switched to a keyed Fragment
- Minor: CompliancePage summary-card grid no longer strands a lone card
  on tablet widths

frontend/src/pages/TestsPage.tsx

@@ -149,6 +149,8 @@ export default function TestsPage() {
   const [platformFilter, setPlatformFilter] = useState("");
   const [searchText, setSearchText] = useState("");
   const [showMyTasks, setShowMyTasks] = useState(false);
+  const [showMyReviews, setShowMyReviews] = useState(false);
+  const isReviewLead = user?.role === "red_lead" || user?.role === "blue_lead";
 
   // ── Sort state ────────────────────────────────────────────────────
   const [sortKey, setSortKey] = useState<SortKey>("created_at");
@@ -167,7 +169,13 @@ export default function TestsPage() {
   const filters = useMemo<TestListFilters>(() => {
     const f: TestListFilters = { limit: 200 };
 
-    if (showMyTasks && user) {
+    if (showMyReviews && user && isReviewLead) {
+      // "My reviews" — tests assigned to ME at the red_review/blue_review
+      // gate. Distinct from "My Tasks" below, which covers the later
+      // in_review manager-validation stage regardless of assignment.
+      f.state = user.role === "red_lead" ? "red_review" : "blue_review";
+      f.reviewer_id = user.id;
+    } else if (showMyTasks && user) {
       switch (user.role) {
         case "red_tech":
           f.created_by = user.id;
@@ -192,7 +200,7 @@ export default function TestsPage() {
 
     if (platformFilter) f.platform = platformFilter;
     return f;
-  }, [stateFilter, platformFilter, showMyTasks, user]);
+  }, [stateFilter, platformFilter, showMyTasks, showMyReviews, isReviewLead, user]);
 
   const {
     data: allTests,
@@ -497,7 +505,10 @@ export default function TestsPage() {
             <button
               onClick={() => {
                 setShowMyTasks(!showMyTasks);
-                if (!showMyTasks) setStateFilter("");
+                if (!showMyTasks) {
+                  setShowMyReviews(false);
+                  setStateFilter("");
+                }
               }}
               className={`flex items-center gap-1.5 rounded-lg border px-3 py-2 text-sm font-medium transition-colors ${
                 showMyTasks
@@ -510,6 +521,29 @@ export default function TestsPage() {
             </button>
           )}
 
+          {/* My reviews toggle — red_lead/blue_lead only, the red_review/blue_review
+              lead-review gate assignment queue (distinct from "My Tasks" above,
+              which covers the later in_review manager-validation stage). */}
+          {isReviewLead && (
+            <button
+              onClick={() => {
+                setShowMyReviews(!showMyReviews);
+                if (!showMyReviews) {
+                  setShowMyTasks(false);
+                  setStateFilter("");
+                }
+              }}
+              className={`flex items-center gap-1.5 rounded-lg border px-3 py-2 text-sm font-medium transition-colors ${
+                showMyReviews
+                  ? "border-cyan-500/50 bg-cyan-500/20 text-cyan-400"
+                  : "border-gray-700 bg-gray-800 text-gray-300 hover:border-gray-600"
+              }`}
+            >
+              <Eye className="h-4 w-4" />
+              My Reviews
+            </button>
+          )}
+
           {/* State filter */}
           <div className="flex items-center gap-1.5">
             <Filter className="h-4 w-4 text-gray-500" />
@@ -556,13 +590,14 @@ export default function TestsPage() {
           </div>
 
           {/* Clear filters */}
-          {(stateFilter || platformFilter || searchText || showMyTasks) && (
+          {(stateFilter || platformFilter || searchText || showMyTasks || showMyReviews) && (
             <button
               onClick={() => {
                 setStateFilter("");
                 setPlatformFilter("");
                 setSearchText("");
                 setShowMyTasks(false);
+                setShowMyReviews(false);
               }}
               className="text-xs text-gray-400 hover:text-white transition-colors"
             >
@@ -572,9 +607,14 @@ export default function TestsPage() {
         </div>
 
         {/* Active filter summary */}
-        {(stateFilter || showMyTasks) && (
+        {(stateFilter || showMyTasks || showMyReviews) && (
           <div className="mt-3 flex items-center gap-2 text-xs text-gray-400">
             <span>Showing:</span>
+            {showMyReviews && (
+              <span className="rounded-full border border-cyan-500/30 bg-cyan-500/10 px-2 py-0.5 text-cyan-400">
+                My Reviews
+              </span>
+            )}
             {showMyTasks && (
               <span className="rounded-full border border-cyan-500/30 bg-cyan-500/10 px-2 py-0.5 text-cyan-400">
                 {myTasksLabel}
@@ -629,11 +669,11 @@ export default function TestsPage() {
         <div className="rounded-xl border border-gray-800 bg-gray-900 p-6">
           <div className="mb-4 flex items-center justify-between">
             <h2 className="text-lg font-semibold text-white">
-              {showMyTasks ? myTasksLabel : "All Tests"}
+              {showMyReviews ? "My Reviews" : showMyTasks ? myTasksLabel : "All Tests"}
             </h2>
             <span className="text-sm text-gray-400">{tests.length} tests</span>
           </div>
-          <TestTable tests={tests} columns={mainTableColumns} sortKey={sortKey} sortDir={sortDir} handleSort={handleSort} navigate={navigate} formatDate={formatDate} emptyMessage={showMyTasks ? "No pending tasks for your role." : "No tests found matching your filters."} />
+          <TestTable tests={tests} columns={mainTableColumns} sortKey={sortKey} sortDir={sortDir} handleSort={handleSort} navigate={navigate} formatDate={formatDate} emptyMessage={showMyReviews ? "No tests currently assigned to you for review." : showMyTasks ? "No pending tasks for your role." : "No tests found matching your filters."} />
         </div>
       )}
     </div>