Clean up unused Python script wrappers

[ryan-reid]

Summary

• remove the unused legacy paginated skill extraction prototypes
• remove the dev-only UI validation helper that depended on that legacy code
• remove top-level compatibility wrapper scripts and import shims
• keep scripts/generate_reports.py as the single top-level rebuild command, with focused tools available through python -m cli.
• update docs, tests, devtools, and wiki footer text for the cleaned script layout

Verification

• python -m unittest discover -s tests
• python scripts/generate_reports.py