fix(dialog): improve escape key handling for dialogs

The handling of the Escape key has been refined to ensure that it
closes the correct dialog based on the current state. Additionally,
the z-index for the compare dialog backdrop has been updated to
ensure proper layering with other dialogs.

- Enhanced Escape key functionality for better user experience
- Updated z-index for compare dialog backdrop to avoid overlap

src/App.svelte

@@ -3967,10 +3967,10 @@
       helpOpen = false;
       return;
     }
-    if (event.key === "Escape" && fileHistoryDialogOpen && !isBusy) closeFileHistoryDialog();
+    if (event.key === "Escape" && compareDialogOpen) closeCompareDialog();
+    else if (event.key === "Escape" && fileHistoryDialogOpen && !isBusy) closeFileHistoryDialog();
     else if (event.key === "Escape" && repoTabContextMenu) closeRepoTabContextMenu();
     else if (event.key === "Escape" && pendingDiscard && !isBusy) closeDiscardConfirm();
-    else if (event.key === "Escape" && compareDialogOpen) closeCompareDialog();
     else if (event.key === "Escape" && newBranchCommit) newBranchCommit = null;
     else if (event.key === "Escape" && renameBranchTarget) renameBranchTarget = null;
     else if (event.key === "Escape" && deleteBranchTarget) closeDeleteBranchDialog();

src/app.css

@@ -2882,6 +2882,7 @@
     overflow: hidden;
   }
   .file-history-dialog-backdrop { z-index: 70; }
+  .compare-dialog-backdrop { z-index: 80; }
   .file-history-dialog {
     display: grid;
     grid-template-rows: auto minmax(0, 1fr);

src/lib/components/CompareDialog.svelte

@@ -216,7 +216,7 @@
 </script>
 
 <div
-  class="dialog-backdrop"
+  class="dialog-backdrop compare-dialog-backdrop"
   role="presentation"
 >
   <div class="dialog compare-dialog" role="dialog" aria-modal="true" aria-label="Commit comparison" tabindex="-1">