PR_26175_DELTA_006: add runtime service test lane

[ToolboxAid]

Summary

• Repaired/rebased PR_26175_DELTA_006-page-service-test-lanes onto current main at 7bdcdfed1.
• Replace the team-specific Delta validation harness approach with a service-level runtime test command.
• Add npm run test:service:runtime using the existing scripts/run-node-test-files.mjs runner.
• Keep npm test as the broader site-wide/all-tests command path.
• Align ReplayTimeline with the existing shared cloneRuntimeValue(...) helper so replay fallback behavior is testable through the runtime service command.

Validation

• node --check src/engine/replay/ReplayTimeline.js
• npm run test:service:runtime (7/7 targeted Node test files passed)
• package command assertion for test:service:runtime, no test:delta-runtime, and existing npm test
• absence check for scripts/run-delta-runtime-validation.mjs
• no Delta-named command matches in package.json, scripts, or replay source
• git diff --check

Reports

• docs_build/dev/reports/PR_26175_DELTA_006-page-service-test-lanes.md
• docs_build/dev/reports/codex_review.diff
• docs_build/dev/reports/codex_changed_files.txt
• tmp/PR_26175_DELTA_006-page-service-test-lanes_delta.zip

Notes

• Supersedes the draft team-specific harness direction in PR PR_26175_DELTA_006: add runtime validation harness #188, but does not close it without OWNER approval.
• Per recovery flow, this update stops after repairing PR_26175_DELTA_006: add runtime service test lane #189 because PR_26175_DELTA_006 is not merged yet.