fix(ui): link CLI download to GitHub releases for all platforms (#27805)

The Help page only offered the server's Linux binary served from the pod, which is the wrong architecture for macOS/Windows/arm clients and surprises users with a large (~200MB) download. Add an "All platforms" link to the GitHub releases page for the running server version so users can choose the right binary; released versions deep-link to their tag and dev builds fall back to the releases list.

Signed-off-by: KKamJi <xowl5460@naver.com>

Author: KKamJi98

ui/src/app/help/components/help.test.ts

@@ -0,0 +1,16 @@
+import {cliDownloadURL, RELEASES_URL} from './help';
+
+test('links released versions to their GitHub release tag', () => {
+    expect(cliDownloadURL('v3.4.1')).toBe(`${RELEASES_URL}/tag/v3.4.1`);
+    expect(cliDownloadURL('v3.4.0-rc1')).toBe(`${RELEASES_URL}/tag/v3.4.0-rc1`);
+});
+
+test('falls back to the releases list for dev builds and unknown versions', () => {
+    // dev builds carry semver build metadata
+    expect(cliDownloadURL('v3.5.0+0dc5b3f')).toBe(RELEASES_URL);
+    // empty/unavailable version
+    expect(cliDownloadURL('')).toBe(RELEASES_URL);
+    expect(cliDownloadURL(undefined as unknown as string)).toBe(RELEASES_URL);
+    // anything that is not a recognizable version
+    expect(cliDownloadURL('latest')).toBe(RELEASES_URL);
+});

ui/src/app/help/components/help.tsx

@@ -7,6 +7,17 @@ import classNames from 'classnames';
 
 require('./help.scss');
 
+export const RELEASES_URL = 'https://github.com/argoproj/argo-cd/releases';
+
+// Build a link to the GitHub release matching the running server version, so users can grab a
+// binary for their own OS/arch instead of only the server-arch Linux binary served from the pod.
+// Released versions ("v3.4.1", "v3.4.0-rc1") link to their tag; dev builds carry semver build
+// metadata ("v3.5.0+0dc5b3f") and unknown versions fall back to the releases list.
+export const cliDownloadURL = (version: string): string => {
+    const tag = (version || '').trim();
+    return /^v\d+\.\d+\.\d+(-[0-9A-Za-z.]+)?$/.test(tag) ? `${RELEASES_URL}/tag/${tag}` : RELEASES_URL;
+};
+
 export const Help = () => {
     return (
         <DataLoader
@@ -23,12 +34,14 @@ export const Help = () => {
                 return {
                     binaryUrls: settings.help.binaryUrls || {},
                     // Platform is "<os>/<arch>" (e.g. "linux/amd64"); may be empty.
-                    hostArch: (version.Platform || '').split('/')[1] || ''
+                    hostArch: (version.Platform || '').split('/')[1] || '',
+                    downloadURL: cliDownloadURL(version.Version)
                 };
             }}>
-            {(settings?: {binaryUrls: Record<string, string>; hostArch: string}) => {
+            {(settings?: {binaryUrls: Record<string, string>; hostArch: string; downloadURL: string}) => {
                 const binaryUrls = settings?.binaryUrls || {};
                 const hostArch = settings?.hostArch || '';
+                const downloadURL = settings?.downloadURL || RELEASES_URL;
                 return (
                     <Consumer>
                         {() => (
@@ -45,6 +58,13 @@ export const Help = () => {
                                     <div className='columns large-4 small-6'>
                                         <div className='help-box'>
                                             <p>Want to download the CLI tool?</p>
+                                            {/* Primary option: the GitHub releases page for the running version, where users can
+                                                pick a binary for their own OS/architecture. The in-cluster link below only serves the
+                                                server's Linux binary, which is wrong for macOS/Windows/arm clients. */}
+                                            <a href={downloadURL} target='_blank' rel='noopener noreferrer' className='user-info-panel-buttons argo-button argo-button--base'>
+                                                <i className='fab fa-github' /> All platforms
+                                            </a>
+                                            &nbsp;
                                             {/* Arch-agnostic link: targets the suffix-less /argocd-linux route, which every
                                                 server serves from its own embedded binary regardless of the server's architecture.
                                                 This keeps the UI bundle architecture-independent (no arch baked in) and avoids