feat: typography overhaul, custom scrollbars, import/export, settings UI

Includes changes from prior sessions: Epilogue + Space Mono fonts,
OverlayScrollbars integration, markdown editor fixes, settings dialog,
import/export buttons, and various UI refinements.

src/App.tsx

@@ -39,30 +39,10 @@ export default function App() {
     });
   }, [init]);
 
-  // Save window state + flush board saves before the app window closes
+  // Flush board saves before the app window closes
   useEffect(() => {
     function handleBeforeUnload() {
       useBoardStore.getState().closeBoard();
-
-      // Save window state synchronously-ish (fire and forget)
-      const appWindow = getCurrentWindow();
-      Promise.all([
-        appWindow.outerSize(),
-        appWindow.outerPosition(),
-        appWindow.isMaximized(),
-      ]).then(([size, position, maximized]) => {
-        const settings = useAppStore.getState().settings;
-        saveSettings({
-          ...settings,
-          windowState: {
-            x: position.x,
-            y: position.y,
-            width: size.width,
-            height: size.height,
-            maximized,
-          },
-        });
-      });
     }
     window.addEventListener("beforeunload", handleBeforeUnload);
     return () => {
@@ -70,6 +50,45 @@ export default function App() {
     };
   }, []);
 
+  // Save window state on resize/move (debounced) so it persists without blocking close
+  useEffect(() => {
+    const appWindow = getCurrentWindow();
+    let timeout: ReturnType<typeof setTimeout> | null = null;
+
+    async function saveWindowState() {
+      const [size, position, maximized] = await Promise.all([
+        appWindow.outerSize(),
+        appWindow.outerPosition(),
+        appWindow.isMaximized(),
+      ]);
+      const settings = useAppStore.getState().settings;
+      await saveSettings({
+        ...settings,
+        windowState: {
+          x: position.x,
+          y: position.y,
+          width: size.width,
+          height: size.height,
+          maximized,
+        },
+      });
+    }
+
+    function debouncedSave() {
+      if (timeout) clearTimeout(timeout);
+      timeout = setTimeout(saveWindowState, 500);
+    }
+
+    const unlistenResize = appWindow.onResized(debouncedSave);
+    const unlistenMove = appWindow.onMoved(debouncedSave);
+
+    return () => {
+      if (timeout) clearTimeout(timeout);
+      unlistenResize.then((fn) => fn());
+      unlistenMove.then((fn) => fn());
+    };
+  }, []);
+
   // Listen for custom event to open settings from TopBar or command palette
   useEffect(() => {
     function handleOpenSettings() {