docs: publish parser uncertainty case study

[stacknil]

Summary

• Add an external-readable case study on treating parser uncertainty as evidence.
• Link the case study from the README reviewer entry points.
• Keep supported, skipped, and unsupported line outcomes separate from detector decisions.

Validation

• cmake -S . -B build
• cmake --build build --config Release
• ctest --test-dir build -C Release --output-on-failure (5/5 passed)
• staged diff and relative-link checks passed

Boundaries

• Uses sanitized fixtures and documentation IP ranges only.
• Makes no complete parser coverage, compromise, attribution, or blocking claim.