Add unit tests for channel utilities and configure testing environment

- Created a new test file `channels.test.ts` to cover utilities related to channel configurations and targets.
- Implemented tests for normalizing and grouping selected channels by type, as well as building channel targets from account data and cron history.
- Mocked necessary dependencies to isolate tests and ensure accurate results.
- Updated `vite.config.ts` to set up the testing environment with jsdom and enable global variables for tests.

src/components/channels/ChannelInstructionsPanel.tsx

@@ -0,0 +1,47 @@
+import type { ChannelMeta } from '../../lib/channel-meta';
+
+type ChannelInstructionsPanelProps = {
+  meta: ChannelMeta;
+  title: string;
+  docsLabel: string;
+  diagnosticsNote: string;
+};
+
+export default function ChannelInstructionsPanel({
+  meta,
+  title,
+  docsLabel,
+  diagnosticsNote,
+}: ChannelInstructionsPanelProps) {
+  return (
+    <section className="rounded-[16px] border border-[#E5E8EE] bg-[#FAFBFC] p-4 dark:border-[#2a2a2d] dark:bg-[#17171a]">
+      <div className="text-[13px] font-medium text-[#171717] dark:text-gray-100">{title}</div>
+      <div className="mt-1 text-[12px] leading-[18px] text-[#99A0AE] dark:text-gray-500">
+        {docsLabel}
+      </div>
+
+      <div className="mt-3 space-y-2">
+        <div className="rounded-[12px] border border-dashed border-[#DCE5F1] bg-white px-3 py-2 text-[12px] leading-[18px] text-[#525866] dark:border-[#2a2a2d] dark:bg-[#101013] dark:text-gray-300">
+          {meta.description}
+        </div>
+
+        {meta.instructions.length > 0 ? (
+          <ol className="space-y-2">
+            {meta.instructions.map((instruction) => (
+              <li
+                key={instruction}
+                className="rounded-[12px] border border-[#E5E8EE] bg-white px-3 py-2 text-[12px] leading-[18px] text-[#525866] dark:border-[#2a2a2d] dark:bg-[#101013] dark:text-gray-300"
+              >
+                {instruction}
+              </li>
+            ))}
+          </ol>
+        ) : null}
+      </div>
+
+      <div className="mt-3 rounded-[12px] bg-[#EFF6FF] px-3 py-2 text-[12px] leading-[18px] text-[#2B4E8C] dark:bg-[#1d2633] dark:text-[#93c5fd]">
+        {diagnosticsNote}
+      </div>
+    </section>
+  );
+}