feat(mornye): separate Search into a circular navigation button

Keep Home, Library, and Repo in the glass capsule while Search remains accessible on the right. Preserve compact transitions and allow returning to Home when Search is active.

test/mornye_bottom_bar_test.dart

@@ -23,14 +23,12 @@ void main() {
   late MornyeChromeController chrome;
   late ScrollController scroll;
   late int searches;
-  late int selected;
   final capture = GlobalKey();
 
   setUp(() {
     chrome = MornyeChromeController();
     scroll = ScrollController();
     searches = 0;
-    selected = 0;
   });
   tearDown(() {
     chrome.dispose();
@@ -109,11 +107,13 @@ void main() {
                 ],
                 selectedIndex: activeTab?.value ?? 0,
                 onSelected: (index) {
-                  selected = index;
                   activeTab?.value = index;
                 },
                 onHome: chrome.expand,
-                onSearch: () => searches++,
+                onSearch: () {
+                  searches++;
+                  activeTab?.value = 3;
+                },
                 blurEnabled: blur,
               ),
             ),
@@ -147,21 +147,25 @@ void main() {
         (3, 'Search'),
         (0, 'Home'),
       ]) {
-        await tester.tapAt(
-          tester.getCenter(
-            find
-                .descendant(
-                  of: find.byType(MornyeTabBar),
-                  matching: find.text(label),
-                )
-                .first,
-          ),
-        );
+        if (index == 3) {
+          await tester.tap(find.byTooltip('Search'));
+        } else {
+          await tester.tapAt(
+            tester.getCenter(
+              find
+                  .descendant(
+                    of: find.byType(MornyeTabBar),
+                    matching: find.text(label),
+                  )
+                  .first,
+            ),
+          );
+        }
         await tester.pumpAndSettle();
         expect(activeTab.value, index);
         final tabIcons = find.descendant(
           of: find.byType(MornyeTabBar),
-          matching: find.byIcon(index == 3 ? Icons.search : Icons.home),
+          matching: find.byIcon(Icons.home),
         );
         // Edge icons stay in the glass bar's selected/unselected layers at
         // rest, so the pill can reveal their red state during a held drag.
@@ -189,7 +193,7 @@ void main() {
         await tester.pumpAndSettle();
         expect(
           tester.widget<MornyeTabBar>(find.byType(MornyeTabBar)).selectedIndex,
-          index,
+          index == 3 ? -1 : index,
         );
       }
     });
@@ -236,16 +240,18 @@ void main() {
       },
     );
 
-    testWidgets('four tabs keep Search at the right edge (glass: $blur)', (
+    testWidgets('Search is a separate circle at the right (glass: $blur)', (
       tester,
     ) async {
       await pumpShell(tester, blur: blur);
       final tabs = find.byType(MornyeTabBar);
-      final search = find
-          .descendant(of: tabs, matching: find.text('Search'))
-          .first;
+      final search = find.byKey(const ValueKey('mornye-compact-search'));
       final repo = find.descendant(of: tabs, matching: find.text('Repo')).first;
-      expect(tester.widget<MornyeTabBar>(tabs).destinations, hasLength(4));
+      expect(tester.widget<MornyeTabBar>(tabs).destinations, hasLength(3));
+      expect(
+        find.descendant(of: tabs, matching: find.text('Search')),
+        findsNothing,
+      );
       expect(
         find.descendant(of: tabs, matching: find.text('Settings')),
         findsNothing,
@@ -254,10 +260,15 @@ void main() {
         tester.getCenter(search).dx,
         greaterThan(tester.getCenter(repo).dx),
       );
+      expect(
+        tester.getRect(search).left - tester.getRect(tabs).right,
+        closeTo(12, 0.1),
+      );
+      expect(tester.getSize(search), const Size(64, 64));
       // The glass renderer paints the labels under a gesture overlay.
       await tester.tapAt(tester.getCenter(search));
       await tester.pumpAndSettle();
-      expect(selected, 3);
+      expect(searches, 1);
       expect(tester.takeException(), isNull);
     });
   }