fix(runway): ISS-004 retry transient Git failures

[sbalabanov]

Summary

Intent:

• Prevent temporary Git process and remote failures from being dead-lettered on their first delivery.
• Preserve terminal merge-result behavior and fail fast for recognizable permanent Git configuration failures.

Changes:

• Add structured Git command errors and a centralized Git classifier for retryability and dependency attribution.
• Preserve Git process causes through Runway merger wrapping and wire the classifier into the primary consumer.
• Cover classifier decisions and verify Runway nacks transient Git failures while rejecting unknown failures.

Reproduction:

• A merge delivery runs git fetch origin or git push origin ... while the remote temporarily resets the connection, producing a wrapped *exec.ExitError.
• Previously Runway registered only generic and MySQL classifiers, so the error stayed non-retryable and the consumer rejected it to the DLQ after one attempt.
• With this change the structured Git error is classified as a retryable dependency failure, so the consumer nacks it for redelivery; authentication, invalid repository/configuration, process-start, and unknown command failures remain non-retryable.

---

_{Generated by the 🪄 pr-create skill in devexp-agent-marketplace}

Test Plan

AI Verification

Validated at 623ae95 on Sep 4 22:20 UTC · 14 files analyzed · 2s

Validator	Status	Issues
fix-disclosure	not_applicable	0
arc-lint	not_applicable	0
visual-web	not_applicable	0
go-thrift-lint	not_applicable	0
android-coverage	not_applicable	0
ios-lint	not_applicable	0
web-lint	not_applicable	0
web-repocheck	not_applicable	0
diff-template	not_applicable	0
go-coverage	not_applicable	0
visual-ios	not_applicable	0
go-proto-lint	not_applicable	0
android-lint	not_applicable	0
java-lint	not_applicable	0
java-coverage	not_applicable	0
uber-one	not_applicable	0
web-typecheck	not_applicable	0
go-gazelle	not_applicable	0
web-coverage	not_applicable	0
web-unit	not_applicable	0
merge-conflict	not_applicable	0
go-lint	not_applicable	0
arc-unit	not_applicable	0
visual-android	not_applicable	0
ios-test	not_applicable	0
ureview	completed	0
custom	not_applicable	0

0 issues detected

_{Skipped validators: claude · EngWiki}

Prior runs

Run at c9ee7a8 on Sep 4 22:19 UTC · 14 files · 2s · 0 issues detected

Issues

T3-ISS-004

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}