Return failure when remote output rejects git push

[ahundt]

Return failure when remote output rejects git push

Summary

rtk git push now returns exit status 1 when remote output reports a rejection even if the child process exits 0. RTK retains the server diagnostic and does not print a successful ref summary for the rejected push.

Before and after

Remote output	Before	After
[remote rejected] main -> main (push declined) with exit 0	RTK could print a success summary and return 0.	RTK retains the diagnostic and returns 1.
GH013: Repository rule violations found with exit 0	A server-side ruleset failure could be hidden by the zero process status.	RTK classifies the push as failed.
pre-receive hook declined with exit 0	The rejection could be treated as ordinary progress.	RTK returns failure and retains the message.
Ordinary progress with no rejection marker	A broad check could misclassify a successful push.	The existing success summary remains unchanged.

Implementation

src/cmds/git/git.rs reuses push_output_indicates_rejection in both GitPushLineHandler::format_summary and run_push. The classifier covers the known remote markers [remote rejected], [rejected], GH013, push declined, pre-receive hook declined, and error: failed to push, with case-insensitive matching where server capitalization varies.

Scope and limitation

This corrects known server and ruleset messages without changing unrelated Git commands. Git normally returns a non-zero status for rejection; a new server wording that contains none of the known markers still depends on the underlying process status and should receive a focused regression case when observed.

Verification

• Focused tests cover zero-exit rejection output, server variants, capitalization, retained diagnostics, and non-rejection progress.
• The full branch suite passes with 2,564 tests passed and 8 ignored.
• cargo clippy --all-targets --all-features -- -D warnings, cargo fmt --all -- --check, and git diff --check pass.

[CLAassistant]

All committers have signed the CLA.