RESULT: SUCCESS

FILES CHANGED:
- jq_interpreter/parser.py
- tests/test_service_lexical_bindings.py

SUMMARY:
Implemented lexical variable scope validation and added binding tests for generators, shadowing, patterns, keyword names, and scope isolation.

Verification: 111 tests passed; conformance slice passed 89 cases with 0 failures and 0 errors.

BLOCKERS:
- None