✨ 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/utils.ts

@@ -6,6 +6,7 @@ import { getSymbolicIcon } from "./apps";
 
 import GLib from "gi://GLib?version=2.0";
 import Gio from "gi://Gio?version=2.0";
+import Xdp from "gi://Xdp?version=1.0";
 
 
 /** gnim doesn't export this, so we need to do it again */
@@ -13,9 +14,9 @@ export type WidgetNodeType = Array<JSX.Element> | JSX.Element | number | string
 
 export const decoder = new TextDecoder("utf-8"),
     encoder = new TextEncoder();
-
 export const time = createPoll(GLib.DateTime.new_now_local(), 500, () => 
     GLib.DateTime.new_now_local());
+export const XdgPortal = Xdp.Portal.new();
 
 export function getHyprlandInstanceSig(): (string|null) {
     return GLib.getenv("HYPRLAND_INSTANCE_SIGNATURE");
@@ -155,6 +156,15 @@ export function transformWidget<ValueType = unknown>(
     : fn(v));
 }
 
+export function filter<ValueType = unknown, FilterReturnType = unknown>(
+    v: Accessor<Array<ValueType>>|Array<ValueType>, 
+    fn: (v: ValueType, i: number, array: Array<ValueType>) => FilterReturnType
+): Array<ValueType>|Accessor<Array<ValueType>> {
+    return ((v instanceof Accessor) ?
+        v(v => v.filter((it, i, arr) => fn(it, i, arr)))
+    : v.filter((it, i, arr) => fn(it, i, arr)));
+}
+
 export function makeDirectory(dir: string): void {
     execAsync([ "mkdir", "-p", dir ]);
 }