refactor: enhance extension installation process with overwrite confirmation

if store extension exists in DB but not disk, also ask if need to overwrite it.

apps/desktop/src/routes/app/extension/store/[identifier]/+page.svelte

@@ -81,7 +81,6 @@
 			.installFromTarballUrl(tarballUrl, installDir, installExtras)
 			.then(() => toast.success(`Plugin ${ext.name} Installed`))
 			.then((loadedExt) => {
-				console.log("loadedExt", loadedExt);
 				supabaseAPI.incrementDownloads({
 					identifier: ext.identifier,
 					version: ext.version
@@ -151,7 +150,6 @@
 </script>
 
 <svelte:window on:keydown={handleKeydown} />
-<Button onclick={() => toast.success("Hello")}>Toast</Button>
 <Button
 	variant="outline"
 	size="icon"

packages/extension/src/install.ts

@@ -55,6 +55,25 @@ export async function installTarball(
 				}
 				await fs.remove(extInstallPath, { recursive: true })
 			}
+
+			// find extension in db, if exists, ask user if they want to overwrite it
+			const exts = await db.getAllExtensionsByIdentifier(manifest.kunkun.identifier)
+			if (exts.length > 0) {
+				const overwrite = await dialog.ask(
+					`Extension ${manifest.kunkun.identifier} already exists in database (but not on disk), do you want to overwrite it?`
+				)
+				if (!overwrite) {
+					return Promise.reject("Extension Already Exists")
+				}
+				if (exts[0].path) {
+					console.log(
+						"delete extension in db (overwrite in order to install a new version)",
+						exts[0].path
+					)
+					await db.deleteExtensionByPath(exts[0].path)
+				}
+			}
+
 			await fs.rename(decompressDest, extInstallPath)
 			await db.createExtension({
 				identifier: manifest.kunkun.identifier,