Summary

• cache per-scope binding and reserved-name analysis inside VariableShortener
• reuse that cached analysis for both _scope_bindings and _local_scope_state
• localize fix_missing_locations to appended public alias statements instead of rescanning the whole tree

Validation

• .venv/bin/python -m pytest -q
• git diff --check

Notes

• I tested a few additional reserved-name optimizations locally and dropped them because they regressed end-to-end package timings; this PR keeps only the changes that held up cleanly.