Allow copying sidenote text when explicitly selected

If the selection is entirely within a sidenote or marginnote,
allow normal copy behavior. Only strip sidenotes from copied
text when selecting verse content that includes sidenotes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

kjvstudy_org/templates/chapter.html

@@ -47,14 +47,6 @@
     cursor: pointer;
     transition: all 0.3s ease;
     position: relative;
-    user-select: none;
-}
-
-.sidenote::selection,
-.marginnote::selection,
-.sidenote *::selection,
-.marginnote *::selection {
-    background: transparent;
 }
 
 label.sidenote-number {
@@ -741,12 +733,22 @@ document.addEventListener('DOMContentLoaded', function() {
     });
 
     // Clean copied text to exclude sidenotes, verse numbers, and margin elements
+    // But allow copying if selection is entirely within a sidenote
     document.addEventListener('copy', function(e) {
         const selection = window.getSelection();
         if (!selection.rangeCount) return;
 
-        // Create a document fragment from the selection
         const range = selection.getRangeAt(0);
+
+        // Check if selection is entirely within a sidenote or marginnote
+        const container = range.commonAncestorContainer;
+        const parentEl = container.nodeType === Node.TEXT_NODE ? container.parentElement : container;
+        if (parentEl && parentEl.closest('.sidenote, .marginnote')) {
+            // Allow normal copy behavior for sidenote content
+            return;
+        }
+
+        // Create a document fragment from the selection
         const fragment = range.cloneContents();
 
         // Create a temporary container