feat: 应用图标 + 浅色/深色主题 + 消息复制 + 详情可选中复制

实现 4 个用户需求:

1. 应用图标(Gotify Ducker 吉祥物)
   - Assets/gotify-mascot.png:用户提供的 PNG(196x196)
   - Assets/Build-Icon.ps1:用 System.Drawing 高质量缩放生成多分辨率 ICO(16/24/32/48/64/128/196),PNG 数据嵌入 ICO 容器(Win10+ 原生支持)
   - Assets/gotify-mascot.ico:7 个分辨率的 PNG-in-ICO,41KB
   - WindowsGotify.csproj 加 <ApplicationIcon> 让 EXE 资源带这个图标
   - csproj 加 <None Update=Assets\gotify-mascot.ico><CopyToOutputDirectory> 发布时一并拷
   - TrayIconService 加 LoadMascotIcon() 静态方法,优先从 EXE 同目录 Assets\ 下找,找不到回退到 SystemIcons.Application
   - Windows 通知中心的 toast 会自动用 ApplicationIcon(无需单独设)

2. 浅色/深色主题
   - AppConfig 新增 UiConfig { Theme: "Light"|"Dark"|"System" }
   - Themes/Light.xaml + Themes/Dark.xaml:两个 ResourceDictionary,定义 WindowBackground/CardBackground/CardAltBackground/BorderColor/PrimaryText/SecondaryText/MutedText/AccentBrush/SuccessDot/ErrorDot/PendingDot/PriorityUrgent/High/Normal/Low 等
   - Services/ThemeService.cs:静态类,Apply(name) 卸载旧主题字典 + 加载新主题字典到 Application.Resources.MergedDictionaries,Changed 事件,Toggle() 切换
   - MainWindow.xaml 所有颜色全部改用 {DynamicResource Xxx},主题切换时立刻刷新
   - PriorityToBrushConverter 改用 Application.Current.TryFindResource("PriorityXxx") 拿色,跟着主题走
   - 主窗右上角加 ☼/☾ 切换按钮,点一下切主题并自动写回 config.json

3. 消息正文复制按钮
   - 详情面板"消息正文"标签右侧加 [复制] 按钮
   - CopyMessageButton_Click:用 System.Windows.Clipboard.SetText 把全文(应用名/标题/时间/优先级/正文/URL)写进剪贴板
   - 按钮反馈:复制后短暂显示"已复制"1.5 秒再恢复
   - BuildFullMessageText 静态方法统一格式化

4. 详情面板可选中复制
   - DetailMessage 从 TextBlock 改成 TextBox(IsReadOnly=True, BorderThickness=0, Background=Transparent, IsReadOnlyCaretVisible=True)
   - DetailTitle / DetailUrl 也改成 TextBox IsReadOnly,用户能 Ctrl+A 全选、鼠标拉黑
   - DetailUrl 双击打开(之前是单击,TextBlock 没法选中;TextBox 单击会进入文字选择模式影响双击识别,所以改成双击)

WPF+WinForms 双开:Application/Brush/Color/Clipboard/Button 多个类型两个命名空间都有,ThemeService/ValueConverters/MainWindow.xaml.cs 都加 using alias 固定走 WPF 的;TrayIconService 加 using System.IO 补 Path/File。

实测:新进程跑起来后 ApplicationCache refreshed count=6(用户新建了一个 app),WebSocket connected,真实消息流处理正常(短信号码 19999999999/15889931832),通知弹出。

Assets/Build-Icon.ps1

@@ -0,0 +1,84 @@
+# 从 Assets/gotify-mascot.png 生成多分辨率 ICO
+# 输出:Assets/gotify-mascot.ico
+param(
+    [string]$Png = "$PSScriptRoot\gotify-mascot.png",
+    [string]$Ico = "$PSScriptRoot\gotify-mascot.ico"
+)
+
+Add-Type -AssemblyName System.Drawing
+
+$src = [System.Drawing.Image]::FromFile((Resolve-Path $Png))
+$srcW = $src.Width
+$srcH = $src.Height
+
+# 多分辨率列表(像素) — 包含原始尺寸
+$sizes = @(16, 24, 32, 48, 64, 128, 196) | Where-Object { $_ -le [math]::Max($srcW, $srcH) }
+if (($srcW, $srcH) -notin $sizes) { $sizes += ,($srcW, $srcH) | Out-Null }
+$sizes = $sizes | Sort-Object -Unique
+
+# 1) 把每个分辨率的位图渲染成 PNG 字节
+$entries = @()
+foreach ($sz in $sizes) {
+    $bmp = New-Object System.Drawing.Bitmap $sz, $sz, ([System.Drawing.Imaging.PixelFormat]::Format32bppArgb)
+    $g = [System.Drawing.Graphics]::FromImage($bmp)
+    $g.InterpolationMode = [System.Drawing.Drawing2D.InterpolationMode]::HighQualityBicubic
+    $g.SmoothingMode = [System.Drawing.Drawing2D.SmoothingMode]::HighQuality
+    $g.PixelOffsetMode = [System.Drawing.Drawing2D.PixelOffsetMode]::HighQuality
+    $g.Clear([System.Drawing.Color]::Transparent)
+    $g.DrawImage($src, 0, 0, $sz, $sz)
+    $g.Dispose()
+
+    $ms = New-Object System.IO.MemoryStream
+    $bmp.Save($ms, [System.Drawing.Imaging.ImageFormat]::Png)
+    $pngBytes = $ms.ToArray()
+    $ms.Dispose()
+    $bmp.Dispose()
+
+    $entries += [pscustomobject]@{
+        Width = $sz
+        Height = $sz
+        Bytes = $pngBytes
+    }
+}
+$src.Dispose()
+
+# 2) 组装 ICO 文件
+#   ICONDIR (6 bytes)
+#   ICONDIRENTRY * N (16 bytes each)
+#   Image data
+
+$out = New-Object System.IO.MemoryStream
+$bw = New-Object System.IO.BinaryWriter $out
+
+# ICONDIR
+$bw.Write([uint16]0)        # Reserved
+$bw.Write([uint16]1)        # Type: 1 = ICO
+$bw.Write([uint16]$entries.Count)  # Count
+
+# ICONDIRENTRY (16 bytes each)
+$dataOffset = 6 + 16 * $entries.Count
+foreach ($e in $entries) {
+    $w = if ($e.Width  -ge 256) { 0 } else { $e.Width  }
+    $h = if ($e.Height -ge 256) { 0 } else { $e.Height }
+    $bw.Write([byte]$w)             # Width
+    $bw.Write([byte]$h)             # Height
+    $bw.Write([byte]0)              # Color count (0 = >256 colors)
+    $bw.Write([byte]0)              # Reserved
+    $bw.Write([uint16]1)            # Color planes
+    $bw.Write([uint16]32)           # Bits per pixel
+    $bw.Write([uint32]$e.Bytes.Length)
+    $bw.Write([uint32]$dataOffset)
+    $dataOffset += $e.Bytes.Length
+}
+
+# Image data
+foreach ($e in $entries) {
+    $bw.Write($e.Bytes)
+}
+
+$bw.Flush()
+[System.IO.File]::WriteAllBytes($Ico, $out.ToArray())
+$bw.Dispose()
+$out.Dispose()
+
+Write-Host "ICO built: $Ico ($((Get-Item $Ico).Length) bytes, $($entries.Count) sizes: $($sizes -join ','))"