fix: stabilize preview-to-editor SyncTeX jumps

- Replace jumpHandledRef boolean with lastHandledTargetRef so rapid
  preview clicks are tracked per-target and not swallowed by a stale
  global flag.
- Wrap the Monaco editor in a ResizeObserver container and call
  editor.layout() before revealRangeInCenter so container resizes
  (sidebar, window) don't break scroll-to-target.
- Harden tinymist/preview/scrollSource handler against missing or
  non-string filepath payloads.

typst-leaf-frontend/src/components/Editor.tsx

@@ -142,10 +142,32 @@ export function EditorView() {
     );
   };
 
-  // Jump target effect — reactive (no polling)
+  // Resize observer keeps Monaco laid out when the flex container changes
-  const jumpHandledRef = useRef(false);
+  // size (sidebar toggles, window resize, etc.). Without this, revealRange
+  // and cursor positioning can be off after a layout change.
+  const editorContainerRef = useRef<HTMLDivElement | null>(null);
+  useEffect(() => {
+    if (!editorReady || !editorContainerRef.current || !editorRef.current) {
+      return;
+    }
+    const editor = editorRef.current;
+    const ro = new ResizeObserver(() => editor.layout());
+    ro.observe(editorContainerRef.current);
+    return () => ro.disconnect();
+  }, [editorReady]);
+
+  // Jump target effect — reactive (no polling). Track the last handled
+  // target by object identity so rapid clicks don't get swallowed by a stale
+  // boolean flag, and call editor.layout() before reveal so container
+  // resizes don't break the scroll.
+  const lastHandledTargetRef = useRef<{
+    file: string;
+    start?: [number, number];
+    end?: [number, number];
+  } | null>(null);
   useEffect(() => {
     if (!state.jumpTarget || !editorRef.current || !monaco || !model) return;
+    if (state.jumpTarget === lastHandledTargetRef.current) return;
 
     const target = state.jumpTarget;
     const modelUri = model.uri.toString();
@@ -155,8 +177,7 @@ export function EditorView() {
       : null;
 
     if (!expectedModelUri || modelUri !== expectedModelUri) return;
-    if (jumpHandledRef.current) return;
+    lastHandledTargetRef.current = target;
-    jumpHandledRef.current = true;
 
     let selection: Monaco["Selection"] | null = null;
     if (target.start && target.end) {
@@ -176,6 +197,7 @@ export function EditorView() {
     }
 
     if (selection) {
+      editorRef.current.layout();
       editorRef.current.setSelection(selection);
       editorRef.current.revealRangeInCenter(selection);
       editorRef.current.focus();
@@ -184,11 +206,6 @@ export function EditorView() {
     dispatch({ type: "clearJumpTarget" });
   }, [state.jumpTarget, model, monaco, uri]);
 
-  // Reset jumpHandledRef when a new jump target arrives
-  if (state.jumpTarget === null) {
-    jumpHandledRef.current = false;
-  }
-
   if (!project) {
     return (
       <div className="flex-1 flex items-center justify-center text-zinc-400 text-sm">
@@ -240,7 +257,7 @@ export function EditorView() {
           </button>
         </span>
       </div>
-      <div className="flex-1 min-h-0">
+      <div ref={editorContainerRef} className="flex-1 min-h-0">
         <Editor
           defaultLanguage="typst"
           theme="vs"

typst-leaf-frontend/src/lsp.ts

@@ -500,8 +500,16 @@ export async function startLsp(
   // SyncTeX: when user clicks in the preview, tinymist emits this notification
   // with the source file and position. We forward it to the jump handler.
   client.onNotification("tinymist/preview/scrollSource", (params) => {
-    const p = params as { filepath: string; start?: [number, number]; end?: [number, number] };
+    const p = params as {
+      filepath?: string;
+      start?: [number, number];
+      end?: [number, number];
+    };
     if (!onJumpToSource) return;
+    if (typeof p.filepath !== "string") {
+      console.warn("[lsp] tinymist/preview/scrollSource missing filepath", params);
+      return;
+    }
     const filepath = p.filepath.includes("://")
       ? decodeURIComponent(new URL(p.filepath).pathname)
       : p.filepath.replaceAll("\\", "/");