ci(release): 重构发布流水线，新增中文发布说明脚本，更新文档

重构GitHub Actions发布流水线：
- 改为手动触发，支持beta测试和正式发布两种模式
- 自动基于UTC时刻生成BUILD ID作为版本后缀
- 拆分打包签名与发布步骤，新增中文发布说明生成逻辑
新增scripts/release-notes.ps1脚本，用于生成带提交记录的中文发布说明
更新docs/auto-update-plan.md文档，适配新的发布流程并新增对应章节

scripts/release-notes.ps1

@@ -0,0 +1,75 @@
+# Koring Launcher 中文 Release 发布说明生成器
+#
+# 用法（GitHub Actions 中调用）：
+#   ./scripts/release-notes.ps1 -BaseVersion "1.2.0" -FullVersion "1.2.0-2608280224" -Mode "beta" -OutputPath release-notes.md
+#
+# 输出（Markdown，UTF-8）：
+#   # Koring Launcher Releases {BaseVersion}
+#   ## 版本信息
+#   当前版本 {FullVersion}
+#   编译状态：BETA / RUN
+#   ## 更新了什么内容
+#   <details><summary>·Commit 1cf906d</summary>提交说明…</details>（默认折叠）
+
+param(
+  [Parameter(Mandatory = $true)][string] $BaseVersion,
+  [Parameter(Mandatory = $true)][string] $FullVersion,
+  [Parameter(Mandatory = $true)][string] $Mode,
+  [string] $OutputPath = "release-notes.md"
+)
+
+$status = if ($Mode -eq 'beta') { 'BETA' } else { 'RUN' }
+
+$rec = [char]0x1e   # 记录分隔符（每个 commit 一条）
+$sep = [char]0x1f   # 字段分隔符（hash / subject / body）
+$format = "%x1f%H%x1f%s%x1f%b%x1e"
+
+# 自上个 release tag（v*）以来的提交；无 tag 则取全部提交
+$lastTag = git tag --sort=-version:refname 2>$null | Where-Object { $_ -match '^v' } | Select-Object -First 1
+if ($lastTag) {
+  Write-Host "Commits since tag: $lastTag"
+  $raw = git log --format=$format "$lastTag..HEAD"
+} else {
+  Write-Host "No release tags found, listing all commits"
+  $raw = git log --format=$format "HEAD"
+}
+
+$blocks = @()
+foreach ($record in ($raw -split [regex]::Escape($rec))) {
+  if (-not $record) { continue }
+  $parts = $record -split [regex]::Escape($sep)
+  if ($parts.Length -lt 4) { continue }
+  $hash = $parts[1].Trim()
+  $subject = $parts[2].Trim()
+  $body = $parts[3].Trim()
+  if (-not $hash) { continue }
+
+  $short = $hash.Substring(0, [Math]::Min(7, $hash.Length))
+  $inner = $subject
+  if ($body) { $inner += "`n`n$body" }
+
+  $blocks += @"
+<details>
+<summary>·Commit $short</summary>
+
+$inner
+
+</details>
+"@
+}
+
+$commitsSection = if ($blocks.Count -gt 0) { $blocks -join "`n`n" } else { '· 无提交记录' }
+
+$content = @"
+# Koring Launcher Releases $BaseVersion
+
+## 版本信息
+当前版本 $FullVersion
+编译状态：$status
+
+## 更新了什么内容
+$commitsSection
+"@
+
+[System.IO.File]::WriteAllText($OutputPath, $content, [System.Text.UTF8Encoding]::new($false))
+Write-Host "Release notes written to $OutputPath ($($blocks.Count) commits)"