feat(desktop): apply designer icons to apps and Windows setup

apps/desktop/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write apps/desktop/README.md
-README.md: 27988b195c6b3611cda3d5fc04b8a33a4e67a951
-README.zh.md: d3bf48afc9ccfc7b10d90f1e96df5f8a83aedff4
+README.md: 139af236e8be8bcb3dfc1a27f58cd168fd9d3af1
+README.zh.md: 287fe08a1f3e8bf1ae41d00805a485972b2f795f

apps/desktop/README.md

@@ -6,6 +6,10 @@ The desktop application is an Electron shell around the complete dsh Web applica
 
 ## Key technical decisions
 
+The original artwork lives in `resources/icon.png` and `resources/icon.svg`; platform adaptations retain the whale and gradients in `resources/icon-windows.*` and `resources/icon-macos.*`. Export each platform SVG as a transparent 1024×1024 PNG. Electron-builder generates the multi-size ICO for the Windows application, installer, and uninstaller ([Windows icon requirements](https://learn.microsoft.com/en-us/windows/apps/design/iconography/app-icon-construction)). The installation pages use matching artwork in both themes; the uninstaller's welcome and finish pages share `installer/assets/uninstaller-sidebar.png`, converted to a 164×314 BMP during preparation.
+
+The macOS PNG uses an inset rounded background for legacy ICNS packaging, with representations up to 1024 pixels. It is a flattened icon, not an Icon Composer document. Apple's [app icon guidance](https://developer.apple.com/design/human-interface-guidelines/app-icons) describes unmasked layers for Icon Composer; those inputs require a separate macOS export and must not reuse the rounded ICNS artwork. Verify Finder and Dock appearance on supported macOS versions before release.
+
 | Decision | Why | Direct consequence |
 |---|---|---|
 | Release identity | The shell API, Web client, backend, and plugin graph are qualified as one combination; independent versions would create untested combinations and ambiguous update availability. | Electron and `@deepseek-ai/dsh` always have the same exact version. A dsh upgrade is a Desktop release, even when the shell code is unchanged. |

apps/desktop/README.zh.md

@@ -6,6 +6,10 @@
 
 ## 关键技术决策
 
+设计师原稿位于 `resources/icon.png` 和 `resources/icon.svg`；平台适配保留鲸鱼与渐变，分别位于 `resources/icon-windows.*` 和 `resources/icon-macos.*`。将各平台 SVG 导出为透明的 1024×1024 PNG。electron-builder 为 Windows 应用、安装程序和卸载程序生成多尺寸 ICO（[Windows 图标要求](https://learn.microsoft.com/en-us/windows/apps/design/iconography/app-icon-construction)）。安装页面在两种主题下使用匹配的图案；卸载程序的欢迎和完成页共用 `installer/assets/uninstaller-sidebar.png`，准备阶段将其转换为 164×314 BMP。
+
+macOS PNG 使用带留白的圆角底板，供传统 ICNS 打包使用，包含最高 1024 像素的表示。它是扁平图标，并非 Icon Composer 文档。Apple 的[应用图标指南](https://developer.apple.com/design/human-interface-guidelines/app-icons)要求向 Icon Composer 提供未遮罩的图层；这些输入需要在 macOS 上单独导出，不能复用已做圆角的 ICNS 图案。发布前须在支持的 macOS 版本中验收 Finder 和 Dock 的显示效果。
+
 | 决策 | 原因 | 直接结果 |
 |---|---|---|
 | 发布身份 | 桌面壳 API、Web 客户端、后端与插件依赖图作为一个组合完成验证；独立版本会产生未经验证的组合，并让更新可用性含糊不清。 | Electron 与 `@deepseek-ai/dsh` 始终使用同一精确版本。即使桌面壳代码不变，升级 dsh 也必须发布新 Desktop 版本。 |

apps/desktop/electron-builder.config.mjs

@@ -91,6 +91,7 @@ export function createElectronBuilderConfig(
       { from: join(buildPaths.dsh, 'node_modules'), to: 'dsh/node_modules' },
     ],
     mac: {
+      icon: fileURLToPath(new URL('./resources/icon-macos.png', import.meta.url)),
       category: 'public.app-category.developer-tools',
       identity: macOSSigning?.signingIdentity,
       forceCodeSigning: true,
@@ -133,6 +134,7 @@ export function createElectronBuilderConfig(
       )
     },
     win: {
+      icon: fileURLToPath(new URL('./resources/icon-windows.png', import.meta.url)),
       forceCodeSigning: !unsigned,
       signtoolOptions: {
         sign: windowsSigner,
@@ -145,6 +147,8 @@ export function createElectronBuilderConfig(
       target: ['AppImage'],
     },
     nsis: {
+      installerSidebar: join(buildPaths.root, 'installer-ui', 'uninstaller-sidebar.bmp'),
+      uninstallerSidebar: join(buildPaths.root, 'installer-ui', 'uninstaller-sidebar.bmp'),
       include: fileURLToPath(new URL('./scripts/installer.nsh', import.meta.url)),
       oneClick: false,
       perMachine: false,

apps/desktop/scripts/prepare-windows-installer.ps1

@@ -29,7 +29,7 @@ if ($TestProgress) {
     if ($LASTEXITCODE -ne 0) { throw 'Progress timeline regression failed.' }
 }
 Add-Type -AssemblyName System.Drawing
-foreach ($asset in @('brand', 'brand-2x', 'brand-dark', 'brand-dark-2x')) {
+foreach ($asset in @('brand', 'brand-2x', 'brand-dark', 'brand-dark-2x', 'uninstaller-sidebar')) {
     $image = [Drawing.Image]::FromFile((Join-Path $installerRoot "assets/$asset.png"))
     try {
         $bitmap = [Drawing.Bitmap]::new($image.Width, $image.Height, [Drawing.Imaging.PixelFormat]::Format24bppRgb)