Add reproducible report-build acceptance checks

[SRuedesh]

The CYP2D6 DDGI report build should include automated acceptance checks before the report is considered publishable.

1. Fail the build on missing images.
2. Fail the build on broken internal or external links.
3. Fail the build on branch-head model links where immutable release links are required.
4. Fail or explicitly flag empty report sections.
5. Fail or explicitly flag non-positive values used on log-scale ratio plots.
6. Fail or explicitly flag unresolved model snapshot and evaluation-report links.

These checks should prevent technical regressions during repeated report rendering.