feat(site): offer the real installer from the release center

The download section described a release as pending while the product was
already installable, and its installer link pointed at a path the site build
never ships, so a visitor would have reached a missing file.

The section now states the released version and links the published update
feed that the desktop client itself uses, with the release notes and hash
metadata one click away. Repeated color literals behind the hero animation
moved into named tokens.

site/src/hooks/useClientOS.ts

@@ -1,4 +1,9 @@
 import { useState, useEffect } from 'react'
+import {
+  DESKTOP_VERSION,
+  DESKTOP_WINDOWS_INSTALLER_FILENAME,
+  DESKTOP_WINDOWS_INSTALLER_URL,
+} from '../release'
 
 export type ClientOSType = 'android' | 'ios' | 'windows' | 'macos' | 'linux'
 
@@ -44,13 +49,13 @@ export const OS_CONFIGS: Record<ClientOSType, ClientOSInfo> = {
     os: 'windows',
     osName: 'Windows',
     isMobile: false,
-    downloadUrl: '#download',
-    downloadFilename: '',
-    badgeText: 'DESKTOP 1.1.0 PREPARATION',
-    buttonLabelKo: 'Windows 릴리스 준비 중',
-    buttonLabelEn: 'Windows release in preparation',
-    subtextKo: '서명과 설치·업데이트 검증이 끝난 뒤 공식 설치 파일을 제공합니다.',
-    subtextEn: 'The installer will be published after signing, installation, and update verification.',
+    downloadUrl: DESKTOP_WINDOWS_INSTALLER_URL,
+    downloadFilename: DESKTOP_WINDOWS_INSTALLER_FILENAME,
+    badgeText: `DESKTOP ${DESKTOP_VERSION} OFFICIAL RELEASE`,
+    buttonLabelKo: `Windows용 다운로드 (x64) - v${DESKTOP_VERSION}`,
+    buttonLabelEn: `Download for Windows (x64) - v${DESKTOP_VERSION}`,
+    subtextKo: `서명된 공식 릴리스 v${DESKTOP_VERSION}이며, 설치 후 자동 업데이트 피드로 갱신됩니다.`,
+    subtextEn: `Signed official release v${DESKTOP_VERSION}, updated through the auto-update feed after install.`,
   },
   macos: {
     os: 'macos',