feat: theme chrome by palette, selectable text, wap fallback, and library pages

app/lib/presentation/reader/swipe_navigator.dart

@@ -73,6 +73,10 @@ class _SwipeNavigatorState extends State<SwipeNavigator>
 
   bool get _settledAnimating => _settling != null && _settle.isAnimating;
 
+  /// How close to a screen edge a drag must begin to navigate; horizontal
+  /// drags elsewhere belong to text selection.
+  static const _edgeZone = 40.0;
+
   void _onDragStart(DragStartDetails details) {
     if (_settledAnimating) return;
     setState(() => _dragging = true);
@@ -161,24 +165,37 @@ class _SwipeNavigatorState extends State<SwipeNavigator>
               )
             : null;
 
-        return GestureDetector(
-          behavior: HitTestBehavior.deferToChild,
-          onHorizontalDragStart: _onDragStart,
-          onHorizontalDragUpdate: _onDragUpdate,
-          onHorizontalDragEnd: _onDragEnd,
-          child: Stack(
-            children: [
-              if (peek != null) Positioned.fill(child: peek),
-              Transform.translate(
-                offset: Offset(dx, 0),
-                child: widget.child,
-              ),
-            ],
-          ),
+        return Stack(
+          children: [
+            if (peek != null) Positioned.fill(child: peek),
+            Transform.translate(
+              offset: Offset(dx, 0),
+              child: widget.child,
+            ),
+            // Only horizontal drags that begin at a screen edge navigate;
+            // the strips are translucent, so taps, vertical scrolling and
+            // text selection still pass through everywhere.
+            _edgeStrip(fromLeft: true),
+            _edgeStrip(fromLeft: false),
+          ],
         );
       },
     );
   }
+
+  Widget _edgeStrip({required bool fromLeft}) => Positioned(
+        left: fromLeft ? 0 : null,
+        right: fromLeft ? null : 0,
+        top: 0,
+        bottom: 0,
+        width: _edgeZone,
+        child: GestureDetector(
+          behavior: HitTestBehavior.translucent,
+          onHorizontalDragStart: _onDragStart,
+          onHorizontalDragUpdate: _onDragUpdate,
+          onHorizontalDragEnd: _onDragEnd,
+        ),
+      );
 }
 
 /// The neighboring page's fallback panel while it is still being parsed.