chore(release): v5.18.8

[CybotTM]

Version bump 5.18.7 → 5.18.8.

Changes since v5.18.7:

• docs: reflection-factory refactor trap; CoversClass coverage warnings are CI-only
• docs: heading code-format and Xdebug casing per review
• docs(tdd-discipline): prove a test can fail before calling it done
• docs(tdd-discipline): spell out the restore step of the mutation probe
• docs: five functional/CI lessons — compile-fatal cascades, private-service get(), per-file coverage, JIT-off for functional, per-leg resolution

Surfaces bumped: .claude-plugin/plugin.json, SKILL.md frontmatter version.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

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