fix(detector): detect decorator wrapper replay

[prasannakotyal]

KernelGuard-Red-Submission: 277

Adds a narrow LAST_CALL_REPLAY pass for decorators that wrap custom_kernel with a closure cache.

The detector requires:

• custom_kernel decorated by a locally defined decorator
• a nested wrapper in that decorator
• a fast path returning a cached slot
• a later assignment of the same cached slot from a call to the wrapped function using the wrapper input
• a return of that same cached slot after storage

Local validation:

• UV_CACHE_DIR=/tmp/uvcache uv run python -m py_compile competition_state/kernelguard_mirror/kernelguard.py
• UV_CACHE_DIR=/tmp/uvcache uv run python kernelguard_bypasses/eval_blue_patch.py competition_state/kernelguard_mirror/kernelguard.py
• target artifact /tmp/kg_external_reds/0277_SarahLacard_red-p-124.py is filtered as LAST_CALL_REPLAY

Target red artifact: SarahLacard red 277, decorator wrapper replay variant.

[github-actions]

KernelGuard Blue Evaluation

• Evaluation job: 176
• Blue submission: 148
• 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/25257537056