git: improve error message for remote server failures on push

[murataslan1]

Problem

When git push fails with remote: fatal error in commit_refs (indicating a GitHub server-side issue), VS Code shows the misleading message:

Can't push refs to remote. Try running "Pull" first to integrate your changes.

This is incorrect because the error is caused by the remote server, not by local changes being out of date. Users waste time pulling and retrying when the actual issue is a GitHub outage.

Fix

Added detection for remote: fatal error in commit_refs pattern in the push error handler. When detected, shows a more helpful message directing users to check the remote service status:

Can't push refs to remote. The remote server encountered an internal error. If using GitHub, check https://www.githubstatus.com/ for details.

Changes

• extensions/git/src/api/git.d.ts — Added RemoteInternalError to GitErrorCodes enum
• extensions/git/src/git.ts — Detect fatal error in commit_refs in push stderr before falling through to generic PushRejected
• extensions/git/src/commands.ts — Handle RemoteInternalError with improved error message

Test Plan

1. Simulate a push failure with remote: fatal error in commit_refs in stderr
2. Verify the new message appears mentioning remote server error and githubstatus.com
3. Verify normal push rejections (non-fast-forward) still show the original "Try Pull first" message

Fixes #182679

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

@lszomoru

Matched files:

• extensions/git/src/api/git.d.ts
• extensions/git/src/commands.ts
• extensions/git/src/git.ts

[Copilot]

Pull request overview

Improves the Git extension’s push failure UX by detecting a specific GitHub server-side error (remote: fatal error in commit_refs) and surfacing a more accurate, actionable message instead of suggesting a local “Pull” workaround.

Changes:

• Add a new GitErrorCodes.RemoteInternalError enum value to represent remote server internal failures.
• Detect the fatal error in commit_refs pattern from git push stderr and map it to RemoteInternalError.
• Show a tailored, user-facing error message for RemoteInternalError that points users to GitHub Status.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
extensions/git/src/git.ts	Classifies git push failures containing fatal error in commit_refs as RemoteInternalError.
extensions/git/src/commands.ts	Adds a dedicated notification message for RemoteInternalError during push operations.
extensions/git/src/api/git.d.ts	Extends the public GitErrorCodes enum with RemoteInternalError.

[Copilot]

The githubstatus.com URL is embedded directly in the localized string. Consider using a placeholder (e.g. {0}) and passing the URL as an argument to l10n.t(...) so changing the URL later won’t invalidate existing translations and translators can reposition it as needed.