✨ chore(scripts/utils, scripts/style-handler): add filter() method, change stylesheet target directory

the `filter()` function can both filter a common array and at the same time, it can also filter an Accessor Array(Accessor<Array<T>> and return an Accessor when provided Array is an Accessor Array. Stylesheet directory changed to colorshell's cache dir, making sense, since it's a temporary file generated by the shell

ags/scripts/reload-handler.ts

@@ -8,8 +8,8 @@ import Gio from "gi://Gio?version=2.0";
 
 const monitoringPaths = [ "./scripts", "./window", "./app.ts", "env.d.ts" ];
 
-export function restartInstance(instanceName?: string): void {
-    execAsync(`astal -q ${ instanceName ?? App.instanceName ?? "astal" }`);
+export function restartInstance(): void {
+    execAsync(`astal -q ${ App.instanceName ?? "astal" }`);
     Gio.Subprocess.new(
         ( uwsmIsActive ? 
             [ "uwsm", "app", "--", "ags", "run" ]