ci: add nightly failure issue alerts

[serrrfirat]

Summary

• add a reusable nightly alert script that dedupes GitHub issue alerts by workflow
• extract failed job metadata and high-signal log snippets into the issue body
• wire scheduled E2E and Nightly Deep CI runs to create/update failure issues and close them on recovery

Verification

• bash -n .github/scripts/nightly-alert-issue.sh .github/scripts/nightly-alert-issue.test.sh
• .github/scripts/nightly-alert-issue.test.sh
• git diff --check
• ruby -e 'require "yaml"; ARGV.each { |f| YAML.load_file(f); puts "parsed #{f}" }' .github/workflows/e2e.yml .github/workflows/nightly-deep-ci.yml

Notes

• Alert jobs only run for scheduled workflow runs.
• Repeated failures update the existing issue body instead of adding comments.
• The next scheduled success closes the open alert issue with a recovery note.

[gemini-code-assist]

Code Review

This pull request introduces a bash script and a corresponding test suite to automate the management of GitHub issues for nightly workflow alerts. The script handles creating, updating, or closing issues based on workflow results and includes logic to extract failure excerpts from logs. Feedback suggests increasing the search limit and using quoted titles in the gh issue list command to more reliably identify existing alert issues and prevent duplicates in repositories with many open issues.

[gemini-code-assist]

The default limit for gh issue list is 30. In repositories with a high volume of open issues, the existing alert issue might be missed if it was created some time ago and is no longer among the 30 most recently created or updated issues. Increasing the limit (e.g., to 100) and using a quoted search term for the title will improve the reliability of finding the correct issue to update, preventing duplicate alerts.

Suggested change

	gh issue list \
	--repo "$REPO" \
	--state open \
	--search "${title} in:title" \
	--json number,title \
	--jq 'map(select(.title == env.ALERT_ISSUE_TITLE))[0].number // empty'
	gh issue list \
	--repo "$REPO" \
	--state open \
	--limit 100 \
	--search "\"$title\" in:title" \
	--json number,title \
	--jq 'map(select(.title == env.ALERT_ISSUE_TITLE))[0].number // empty'