fix(frontend): Attempt to resolve TypeError in RichTextInput.svelte

Fixes an issue where `ue.getWordAtDocPos is not a function` would be thrown in `MessageInput.svelte`.

The error was caused by a timing issue where the `getWordAtDocPos` method on the `RichTextInput` component was not available when called from an event handler within the same component.

This change refactors the code to pass the `getWordAtDocPos` function as a callback prop from `RichTextInput` to `MessageInput`, ensuring it's available when needed.

src/lib/workers/pyodide.worker.ts

@@ -40,7 +40,7 @@ async function loadPyodideAndPackages(packages: string[] = []) {
 		packages: ['micropip']
 	});
 
-	let mountDir = '/mnt';
+	const mountDir = '/mnt';
 	self.pyodide.FS.mkdirTree(mountDir);
 	// self.pyodide.FS.mount(self.pyodide.FS.filesystems.IDBFS, {}, mountDir);