fix(detector): detect ModuleType dict replay

[prasannakotyal]

Summary

Targets KG red #318, where custom_kernel aliases a module object's __dict__, stores the first input-derived result through that alias, then returns the alias subscript from an input-independent fast path.

This adds a narrow MODULE_DICT_REPLAY detector. It requires:

• a module-level ModuleType object
• an entrypoint local alias assigned from module.__dict__
• an input-derived assignment to a subscript of that alias
• an input-independent guard over the same alias
• a call-free replay body returning a subscript of that alias

Module attribute replay, exec-defined module entrypoints, and generic vars(...) boxes stay out of scope.

KernelGuard-Red-Submission: 318

Local verification

• red_144_module_dict_replay -> MODULE_DICT_REPLAY, should_filter=True
• red_109_module_attr_replay stayed valid
• red_376_module_exec_attr_define stayed valid
• red_56_vars_box_replay stayed valid
• clean fixtures in eval_blue_patch.py stayed valid
• uv run python -m py_compile kernelguard.py

[github-actions]

KernelGuard Blue Evaluation

• Evaluation job: 75
• Blue submission: 55
• Result: passed
• Target red submission caught: True
• Validation suite: TP 20/20, FP 20/20
• Surgicalness score: 1.0
• Workflow run: https://github.com/SinatrasC/kernelguard/actions/runs/25238621195

[SinatrasC]

Thanks for the KernelGuard Flywheel Campaign contribution. We are not merging this narrow variant separately because the consolidated rule-family implementation in #273 is the merge path for this detector area.