fix(cypher): close #1371 P4 namespaced builtin binder gap - #1388

Summary

• add strict-binder namespace guards so namespaced builtin calls (for example duration.inSeconds(...), date.truncate(...), datetime.fromepoch(...)) do not raise unresolved-alias errors
• cover both property-scan and identifier-scan strict paths in binder.py
• add strict binder tests for namespaced builtins and update strict baseline/parity tests to reflect the P4 closure

Validation

• python -m pytest -q graphistry/tests/compute/gfql/cypher/test_binder.py -k strict_name_resolution_allows_namespaced_builtin_calls
• python -m pytest -q graphistry/tests/compute/gfql/cypher/test_binder_strict_compile_baseline.py
• python -m pytest -q graphistry/tests/compute/gfql/cypher/test_validator_runtime_strict_parity.py
• uv run ruff check graphistry/compute/gfql/frontends/cypher/binder.py graphistry/tests/compute/gfql/cypher/test_binder.py graphistry/tests/compute/gfql/cypher/test_binder_strict_compile_baseline.py graphistry/tests/compute/gfql/cypher/test_validator_runtime_strict_parity.py

Refs #1371