feat: persistent recent files history + fix limit enforcement + fix settings data loss

- Recent files are now persisted to disk and survive restarts
- Max items limit is applied on load (in case setting was reduced)
- Omitted paths regex filtering is now wired up in addToRecentFiles
- Fixed saveAndRefresh() overwriting entire plugin data on settings change
- Debounced disk writes (300ms) to avoid excessive saves on rapid opens

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "waypoint",
-	"version": "1.3.0",
+	"version": "1.4.0",
 	"description": "Calendar, recent files, and custom bookmarks sidebar.",
 	"main": "main.js",
 	"scripts": {