Fix editor not rendering on every other source mode switch

src/lib/components/Editor.svelte

@@ -3392,7 +3392,15 @@
 
 	function createEditor(content: string) {
 		if (!editorElement) return;
-		destroyEditor();
+		// Don't call destroyEditor here — it sets editorReady=false which
+		// triggers reactivity and races with the tick().then() in the
+		// source-mode swap. Just destroy the editor instance directly.
+		if (editor) {
+			editor.destroy();
+			editor = null;
+		}
+		mathObserver?.disconnect();
+		mathObserver = null;
 
 		isLargeDoc = content.length > LARGE_DOC_CHARS;
 		const html = markdownToHtml(content);
@@ -4616,37 +4624,31 @@
 		// Only act if we have a loaded note
 		if (!loadedPath) return;
 
-		// untrack: prevent flushSave() (inside destroyEditor) from adding
+		if (isSource && !lastSourceMode) {
-		// $editorDirty/$activeNote as effect dependencies, which causes
+			// Switching TO source: extract markdown from editor
-		// the effect to re-run and race with tick().then() — resulting in
+			sourceContent = editor ? editorToMarkdown() : ($activeNote?.content ?? '');
-		// the editor failing to render on every other source-mode switch.
+			resetSourceHistory(sourceContent);
-		untrack(() => {
+			lastSourceMode = true;
-			if (isSource && !lastSourceMode) {
+		} else if (!isSource && lastSourceMode) {
-				// Switching TO source: extract markdown from editor
+			lastSourceMode = false;
-				sourceContent = editor ? editorToMarkdown() : ($activeNote?.content ?? '');
+			if (isMobile) {
-				resetSourceHistory(sourceContent);
+				// Mobile: editor stays in DOM, just update its content
-				lastSourceMode = true;
+				const content = sourceContent || ($activeNote?.content ?? '');
-			} else if (!isSource && lastSourceMode) {
+				if (editor) {
-				lastSourceMode = false;
+					ignoreNextUpdate = true;
-				if (isMobile) {
+					editor.commands.setContent(markdownToHtml(content));
-					// Mobile: editor stays in DOM, just update its content
-					const content = sourceContent || ($activeNote?.content ?? '');
-					if (editor) {
-						ignoreNextUpdate = true;
-						editor.commands.setContent(markdownToHtml(content));
-					}
-				} else {
-					// Desktop: destroy old editor, wait for DOM swap, then recreate.
-					destroyEditor();
-					const content = sourceContent || ($activeNote?.content ?? '');
-					tick().then(() => {
-						if (editorElement && !editor) {
-							createEditor(content);
-						}
-					});
 				}
+			} else {
+				// Desktop: destroy old editor, wait for DOM swap, then recreate.
+				destroyEditor();
+				const content = sourceContent || ($activeNote?.content ?? '');
+				tick().then(() => {
+					if (editorElement && !editor) {
+						createEditor(content);
+					}
+				});
 			}
-		});
+		}
 	});
 
 	// Tauri drag-drop listener for OS file drops (browser DragEvent doesn't have files in Tauri)