fix access denied fault error writing js/positions.js (#3652)

if the MagicMirror js folder is not writable (synology nas created by
different user than docker container) there is an uncaught throw

```
[ERROR] EACCES: permission denied, open 'js/positions.js' 
```

add try/catch, output new message, console.error
```text
unable to write js/positions.js with the discovered module positions
make the MagicMirror/js folder writeable by the user starting MagicMirror 
```

MM will start, but no modules will show, as no positions were discovered
this file is used to pass the list from the server side to the browser
side

fixes #3651

Author: sdetweil

CHANGELOG.md

@@ -30,6 +30,7 @@ _This release is scheduled to be released on 2025-01-01._
 - [core] Run code style checks in workflow only once (#3648)
 - [core] Fix animations export #3644 only on server side (#3649)
 - [core] Use project URL in fallback config.
+- [core] fix Access Denied crash writing js/positions.js (on synology nas) #3651. new message, MM starts, but no modules showing
 
 ### Removed
 

js/utils.js

@@ -65,7 +65,12 @@ module.exports = {
 					modulePositions.push(positionName);
 				}
 			});
-			fs.writeFileSync(discoveredPositionsJSFilename, `const modulePositions=${JSON.stringify(modulePositions)}`);
+			try {
+				fs.writeFileSync(discoveredPositionsJSFilename, `const modulePositions=${JSON.stringify(modulePositions)}`);
+			}
+			catch (error) {
+				console.error("unable to write js/positions.js with the discovered module positions\nmake the MagicMirror/js folder writeable by the user starting MagicMirror");
+			}
 		}
 		// return the list to the caller
 		return modulePositions;