chore(scripts): extract version-specific changelog section for release body

scripts/publish-release.ps1

@@ -81,12 +81,18 @@ $Release = $ExistingReleases | Where-Object { $_.tag_name -eq $TagName }
 
 if (-not $Release) {
     $Utf8NoBom = New-Object System.Text.UTF8Encoding($false)
-    $Changelog = [System.IO.File]::ReadAllText((Join-Path $ProjectRoot "CHANGELOG.md"), $Utf8NoBom)
+    $FullChangelog = [System.IO.File]::ReadAllText((Join-Path $ProjectRoot "CHANGELOG.md"), $Utf8NoBom)
+    $VersionPattern = "(?s)## \[$([regex]::Escape($Version))\].*?(?=(?:\r?\n## \[|\z))"
+    if ($FullChangelog -match $VersionPattern) {
+        $ReleaseBody = $matches[0].Trim()
+    } else {
+        $ReleaseBody = $FullChangelog
+    }
     $PayloadPath = Join-Path $DistDir "release_req.json"
     $Payload = @{
         tag_name = $TagName
         name = "Sanctum $TagName (Windows & Linux x86_64)"
-        body = $Changelog
+        body = $ReleaseBody
         draft = $false
         prerelease = $false
     } | ConvertTo-Json -Depth 5