score-pr-checks.yml only validates MODULE.bazel naming, not .bazelrc registry config - missing registry line went undetected in score-crates

## Summary

`score-pr-checks.yml` (bazel-module-name-check job) validates that
`MODULE.bazel`'s module() name matches `^score_[a-z_]+$`, but does not check
`.bazelrc` for the S-CORE custom Bazel registry configuration. As a result, a
repo can silently drift from the standard template without any CI signal.

This actually happened: `score-crates`'s `.bazelrc` was missing the two lines
that every other module (per module_template) has:

common --registry=https://raw.githubusercontent.com/eclipse-score/bazel_registry/main/
common --registry=https://bcr.bazel.build

Without the first line, any module version with an "-score" suffix (e.g.
`rules_rust@0.68.2-score`) cannot be resolved, since those versions only
exist in the S-CORE registry, not the Bazel Central Registry. This went
unnoticed until it caused real build failures.

## Evidence

- `module_template/.bazelrc` (canonical template): has both registry lines.
- `baselibs/.bazelrc`, `persistency/.bazelrc`: have both registry lines.
- `score-crates/.bazelrc`: was missing both lines entirely, with no CI check
catching the discrepancy.

## Suggested improvement

Extend `score-pr-checks.yml` with an additional check (or a new job) that
verifies `.bazelrc` contains the required S-CORE registry line(s), similar to
how the existing job already parses `MODULE.bazel`. Something like:

- name: Check .bazelrc for S-CORE registry
run: |
if [ -f ".bazelrc" ]; then
if ! grep -q "raw.githubusercontent.com/eclipse-score/bazel_registry" .bazelrc; then
echo "S-CORE Bazel registry entry missing from .bazelrc"
fi
fi

This would catch the same class of drift (a repo silently missing a
template-standard `.bazelrc` line) before it causes confusing "-score"
version resolution failures downstream.

## Environment
- cicd-workflows @ main
- module_template @ main
- Repro case: score-crates @ main (as of 2026-08-07, before local fix)

Start with score-pr-checks.yml and inspect the existing bazel-module-name-check job, then compare its validation style with module_template/.bazelrc and the .bazelrc files named in the issue. Add a CI check for the S-CORE registry entry and verify that the workflow reports a missing entry while accepting the standard configuration.

Written by the indexing model from the issue text.