Internal file paths are now Markdown image paths

In the last commit, file paths were implemented to be the full path for the API, however that is not necessary.
Before this change: /data/assets/filename.svg
After: assets/filename.svg
The new method is what SiYuan uses for Markdown images, like ![Drawing](assets/filename.svg)

src/helper.ts

@@ -74,15 +74,20 @@ export function findImgSrc(element: HTMLElement): string | null {
     return null;
 }
 
-export function imgSrcToAbsolutePath(imgSrc: string | null): string | null {
+export function imgSrcToPath(imgSrc: string | null): string | null {
     if (!imgSrc) return null;
 
     const url = new URL(imgSrc);
     imgSrc = decodeURIComponent(url.pathname);
 
     if(imgSrc.startsWith('/assets/')) {
-        return "/data" + imgSrc;
+        return imgSrc.substring(1);
     }
     return null
 
 }
+
+// Helper to safely escape regex special characters
+export function escapeRegExp(string: string) {
+    return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}