fix: tighten note icon typing

src/components/DynamicPropertiesPanel.tsx

@@ -130,8 +130,10 @@ export function DynamicPropertiesPanel({
     const handleFocusNoteIcon = () => {
       const existingIconKey = propertyEntries.find(([key]) => key.toLowerCase() === 'icon')?.[0]
 
-      if (!existingIconKey && !onAddProperty) return
-      if (!existingIconKey) onAddProperty('icon', '')
+      if (!existingIconKey) {
+        if (!onAddProperty) return
+        onAddProperty('icon', '')
+      }
 
       setEditingKey(existingIconKey ?? 'icon')
     }

src/utils/noteIcon.ts

@@ -18,7 +18,7 @@ function isHttpUrl(value: string): boolean {
   }
 }
 
-export function hasNoteIconValue(icon: string | null | undefined): boolean {
+export function hasNoteIconValue(icon: string | null | undefined): icon is string {
   return typeof icon === 'string' && icon.trim().length > 0
 }