fix(memory): include deterministic offline proof in evidence bundles

[mrnicholasbcarter-code]

Summary

• add deterministic, redacted MemoryPlane offline proof metadata
• include the smoke report in generated evidence bundles
• load the sibling smoke module by resolved path when invoked as a script
• add CLI regression coverage and document the evidence contract

Closes #121

Validation

• focused memory/evidence suite: 22 passed
• Ruff: passed
• strict mypy: passed
• pre-commit hook: passed
• full local suite: collection blocked by an existing environment pyOpenSSL/botocore incompatibility in tests/test_vcr_fallback.py

[github-actions]

📊 Benchmark Results

coding

Metric	Fixed	Verdict	Delta
Success Rate	98.0%	99.0%	1.0%
Cost/req	$0.014719	$0.006927	52.9%
p95 Latency	149ms	143ms	-6ms

reasoning

Metric	Fixed	Verdict	Delta
Success Rate	100.0%	98.5%	-1.5%
Cost/req	$0.007437	$0.004384	41.1%
p95 Latency	143ms	143ms	0ms

chat

Metric	Fixed	Verdict	Delta
Success Rate	100.0%	98.5%	-1.5%
Cost/req	$0.000100	$0.001435	-1335.0%
p95 Latency	71ms	143ms	71ms