refactor(mermaid): deduplicate gutter size constant

src/public/app/services/resizer.ts

@@ -1,6 +1,8 @@
 import options from "./options.js";
 import Split from "split.js"
 
+export const DEFAULT_GUTTER_SIZE = 5;
+
 let leftInstance: ReturnType<typeof Split> | null;
 let rightInstance: ReturnType<typeof Split> | null;
 
@@ -26,7 +28,7 @@ function setupLeftPaneResizer(leftPaneVisible: boolean) {
     if (leftPaneVisible) {
         leftInstance = Split(["#left-pane", "#rest-pane"], {
             sizes: [leftPaneWidth, 100 - leftPaneWidth],
-            gutterSize: 5,
+            gutterSize: DEFAULT_GUTTER_SIZE,
             onDragEnd: (sizes) => options.save("leftPaneWidth", Math.round(sizes[0]))
         });
     }
@@ -54,7 +56,7 @@ function setupRightPaneResizer() {
     if (rightPaneVisible) {
         rightInstance = Split(["#center-pane", "#right-pane"], {
             sizes: [100 - rightPaneWidth, rightPaneWidth],
-            gutterSize: 5,
+            gutterSize: DEFAULT_GUTTER_SIZE,
             minSize: [ 300, 180 ],
             onDragEnd: (sizes) => options.save("rightPaneWidth", Math.round(sizes[1]))
         });

src/public/app/widgets/mermaid.ts

@@ -8,6 +8,7 @@ import type FNote from "../entities/fnote.js";
 import type { EventData } from "../components/app_context.js";
 import ScrollingContainer from "./containers/scrolling_container.js";
 import Split from "split.js";
+import { DEFAULT_GUTTER_SIZE } from "../services/resizer.js";
 
 const TPL = `<div class="mermaid-widget">
     <style>
@@ -178,7 +179,7 @@ export default class MermaidWidget extends NoteContextAwareWidget {
             this.splitInstance = Split([ selfEl[0], scrollingContainer[0] ], {
                 sizes: [ 50, 50 ],
                 direction: "vertical",
-                gutterSize: 5,
+                gutterSize: DEFAULT_GUTTER_SIZE,
                 onDragEnd: () => this.zoomHandler?.()
             });
         }