Make implementation conformance declarations total

[dcajal]

Summary

• make each implementation manifest a total conformance declaration against one exact Biosiglib commit
• remove per-specification statuses, entry points, duplicated release metadata, and unused scientific-note statuses
• require both downstream implementations to pin the release target before Biosiglib can be published
• replace manual specification subsets with the generated authoritative catalog

Why

The previous manifest mixed an executable conformance claim with roadmap states. A contributor could exclude specifications from the shared suite by metadata, and several fields duplicated information without being validated against code. The new model has one rule: pin a commit and pass every specification and shared case in it.

Validation

• 17 validator unit tests passed
• repository and both downstream manifests validated
• generated documentation check passed
• strict MkDocs build passed
• Python suite passed: 219 tests
• MATLAB suite passed: 256 tests
• workflow YAML parsing and git diff checks passed