feat: persist maximize state so Restore button shows after reopen

src/ui.tsx

@@ -167,6 +167,17 @@ function Plugin () {
     return function () { off() }
   }, [])
 
+  // Main tells UI the restored placement was maximized → show the Restore button.
+  useEffect(function () {
+    const off = on('SET_MAXIMIZED', function (payload: { maximized: boolean }) {
+      if (payload.maximized) {
+        maximizedRef.current = true
+        setIsMaxToggled(true)
+      }
+    })
+    return function () { off() }
+  }, [])
+
   // Request fresh window data from main (after any action / on start).
   // Pass the REAL iframe size (window.innerWidth/innerHeight) — what Figma actually
   // rendered, not the requested lastSize. Otherwise gaps would be tautological.
@@ -217,7 +228,8 @@ function Plugin () {
           })
           // Maximize is NOT a held dock — persist the exact size+position so re-open
           // restores it (overrides the edge-dock save done by DOCK_REFINE above).
-          emit('SAVE_FREE')
+          // 'maximized: true' so the Restore button shows on next open.
+          emit('SAVE_FREE', { maximized: true })
           refreshInfo()
         })
       })