fix(test): CRLF-proof the AUR packaging guard on Windows CI

git's autocrlf checkout gave PKGBUILD/.SRCINFO CRLF endings on the Windows
runners, so the $-anchored pkgver regex failed ("PKGBUILD must declare a
semver pkgver"). Normalize \r in the test and pin packaging/aur/* to LF
via .gitattributes — makepkg/bash need LF there regardless.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GpEAzmp4bQ5LDSW5ucuXk7

Author: bezzad

.gitattributes

@@ -0,0 +1 @@
+packaging/aur/* text eol=lf

src/Downloader.Desktop.Tests/Unit/AurPackagingTests.cs

@@ -15,8 +15,9 @@ public class AurPackagingTests
     [Fact(Timeout = TestTimeouts.DefaultMs)]
     public void Pkgbuild_and_srcinfo_are_publish_ready_and_in_lockstep()
     {
-        var pkgbuild = File.ReadAllText(FindRepoFile(Path.Combine("packaging", "aur", "PKGBUILD")));
-        var srcinfo = File.ReadAllText(FindRepoFile(Path.Combine("packaging", "aur", ".SRCINFO")));
+        // Normalize CRLF: a Windows git checkout (autocrlf) otherwise breaks the $-anchored matches.
+        var pkgbuild = File.ReadAllText(FindRepoFile(Path.Combine("packaging", "aur", "PKGBUILD"))).Replace("\r", "");
+        var srcinfo = File.ReadAllText(FindRepoFile(Path.Combine("packaging", "aur", ".SRCINFO"))).Replace("\r", "");
 
         var pkgVer = Regex.Match(pkgbuild, @"^pkgver=([0-9]+\.[0-9]+\.[0-9]+)$", RegexOptions.Multiline);
         Assert.True(pkgVer.Success, "PKGBUILD must declare a semver pkgver");