Git status indicators not working with reftable storage backend

Summary

Git status indicators (file colors in project panel, gutter diff markers, branch name) do not appear when opening repositories that use Git's reftable reference storage format (extensions.refstorage=reftable).

This is a regression report / reopen request for #14414, which was closed on Dec 26, 2025 but the issue persists in Zed 0.218.7.

Environment

• Zed version: 0.218.7
• OS: macOS (Darwin 25.2.0)
• Git version: 2.x with reftable support

Steps to Reproduce

# Create a test repo with reftable format
mkdir zed-reftable-test && cd zed-reftable-test
git init --ref-format=reftable
git config user.email "test@example.com"
git config user.name "Test"
echo "hello" > test.txt
git add . && git commit -m "Initial"
echo "modified" >> test.txt

# Open in Zed
zed .

Expected Behavior

• Branch name should appear in the git panel
• test.txt should be highlighted in the project panel

Actual Behavior

• No branch name displayed
• No file status colors in project panel

Potential Cause

Zed uses libgit2 (via the git2 Rust crate) for git operations. libgit2 does not yet support the reftable format. See: libgit2/libgit2#7117

Workaround Suggestion

As mentioned in #14414 comments, a potential workaround would be to shell out to the git CLI for repositories where libgit2 fails to initialize, falling back gracefully until libgit2 gains reftable support.

Impact

This affects users of:

• Large monorepos that use reftable for performance (reftable is faster for repos with many refs)
• Any repository cloned with --ref-format=reftable
• Repositories where git is configured with init.defaultRefFormat=reftable

Related Issues

• [Git 2.45] Reftable storage backend is not supported #14414 (original reftable issue, closed without fix)
• Reftables support libgit2/libgit2#7117 (reftable support PR)