fix: simplify contenteditable replace - restore selection + execCommand, no manual delete

entrypoints/content.ts

@@ -494,37 +494,19 @@ export default defineContentScript({
             snapElement.focus();
           } else if (snapRange) {
             // contenteditable / DOM range path
-            console.log('[LexAI Replace] using DOM range');
+            // Strategy: restore the original selection, then just "type" the new text.
+            // The browser automatically replaces selected text on insert — no manual
+            // deleteContents() needed (and safer since stale range deletes can go wrong).
+            console.log('[LexAI Replace] using DOM range — restoring selection + inserting');
             try {
-              // Strategy: restore the selection from the cloned range, then use
-              // execCommand('insertText') which works reliably on contenteditable.
-              // insertNode() on stale ranges often fails after async operations.
               const sel = window.getSelection();
               if (sel) {
                 sel.removeAllRanges();
-                sel.addRange(snapRange); // restore original selection
-              }
-
-              // Try execCommand first (works on most contenteditable editors)
-              const inserted = document.execCommand('insertText', false, resultText);
-
-              if (!inserted) {
-                // Fallback: direct DOM manipulation
-                snapRange.deleteContents();
-                const textNode = document.createTextNode(resultText);
-                snapRange.insertNode(textNode);
-                if (sel) {
-                  sel.removeAllRanges();
-                  const newRange = document.createRange();
-                  newRange.setStartAfter(textNode);
-                  newRange.collapse(true);
-                  sel.addRange(newRange);
-                }
+                sel.addRange(snapRange); // restore original highlighted selection
               }
+              document.execCommand('insertText', false, resultText); // replaces selection
             } catch (err) {
-              console.warn('[LexAI Replace] range replace failed:', err);
-              // Last resort: execCommand
-              try { document.execCommand('insertText', false, resultText); } catch (_) {}
+              console.warn('[LexAI Replace] execCommand failed:', err);
             }
           } else {
             console.warn('[LexAI Replace] NO VALID SNAP STATE — snapStart:', snapStart, 'snapEnd:', snapEnd, 'snapElement:', snapElement, 'snapRange:', snapRange);