Branches() silently drops any remote branch whose name ends in /HEAD (e.g. origin/release/HEAD) #225

What's wrong

GitBranchParser.Parse (GitIntegration/Parsing/GitBranchParser.cs:~50-58) skips every remote-tracking ref whose full name ends in /HEAD:

bool isRemote = fullRefName.StartsWith(RemotePrefix, StringComparison.Ordinal);
if (isRemote && fullRefName.EndsWith(HeadSuffix, StringComparison.Ordinal))   // HeadSuffix = "/HEAD"
{
    continue;
}

The intent is to hide the symbolic refs/remotes/<remote>/HEAD. Because the check is a suffix match, it also removes real branches. Git accepts release/HEAD, and any other <x>/HEAD, as a branch name (git check-ref-format --branch release/HEAD succeeds).

Reproduction (git 2.43)

git -C up branch release/HEAD main
git -C down fetch
git -C down branch -r
  origin/HEAD -> origin/main
  origin/feature
  origin/main
  origin/release/HEAD          <- git lists it

repo.Branches().ExecuteAsync() on down returns:

feature remote=False
main remote=False
origin/feature remote=True
origin/main remote=True      <- origin/release/HEAD is missing

A local branch with the same name is kept; only the remote-tracking copy disappears. So RemoteOnly() listings, and any "branches on the server" view, lose it with no error.

Suggested fix

• Skip the ref because it is symbolic, not because of how its name ends: add %(symref) to GitOutputFormats.ForEachRefFormat (GitIntegration/Parsing/GitOutputFormats.cs) and skip a remote record when that field is non-empty. This matches git branch -r, which shows origin/HEAD -> origin/main as an alias and lists every real branch normally.
• Correct the nearby remark in GitOutputFormats.cs: with :lstrip=2, the HEAD ref shortens to origin/HEAD, not to the bare origin.

Acceptance

• A parser test in which refs/remotes/origin/release/HEAD (not symbolic) is returned and refs/remotes/origin/HEAD (symbolic) is not.
• An integration test with a remote branch named release/HEAD.