feat: implement server-side architecture cross-validation for RIP-PoA fingerprint checks

[kuanglaodi2-sudo]

Summary

Implements RIP-PoA Architecture Cross-Validation for server-side verification that a miner's claimed device_arch matches their fingerprint data.

What was built

node/arch_cross_validation.py - A comprehensive validation module that:

• Normalizes architecture names (G4, G5, modern_x86, apple_silicon, arm64, etc.)
• Scores SIMD feature consistency (detects cross-architecture SIMD mismatches)
• Scores cache timing profile consistency (L1/L2/L3 latency patterns)
• Scores clock drift magnitude (vintage hardware has more oscillator drift)
• Scores thermal drift consistency
• Scores CPU brand consistency
• Returns a weighted overall score (0.0-1.0) with detailed breakdown

node/test_arch_cross_validation.py - Full unit test suite covering:

• Real hardware validation (G4, modern_x86, apple_silicon)
• Spoofing detection (x86 claiming to be G4)
• Frozen/noisy profile detection (cv=0 = VM/emulator)
• Empty fingerprint handling
• CPU brand cross-validation

Architecture profiles supported

• g4, g5, g3 (PowerPC)
• modern_x86, retro_x86, vintage_x86
• apple_silicon (M1/M2/M3)
• arm64, riscv, sparc, 68k, amiga_68k, power8

Key detection logic

1. SIMD mismatch: G4 claiming x86 SIMD features (SSE2/AVX2) → immediate disqualification
2. CV too stable: Vintage arch (G4) with cv < 0.005 → flagged as suspicious (real vintage crystals are noisy)
3. CV = 0: No oscillator drift → classic frozen VM profile
4. Cache tone ratios: L1/L2 boundary ratios checked against arch-specific ranges
5. CPU brand: Motorola/IBM brands validated against PowerPC claims

References

• Bounty: [BOUNTY] Server-Side Architecture Cross-Validation rustchain-bounties#17
• RIP-PoA hardware fingerprinting system in node/hardware_fingerprint.py
• Existing validation in node/rustchain_v2_integrated_v2.2.1_rip200.py

Testing

cd node && python test_arch_cross_validation.py
# All 10 tests pass

python arch_cross_validation.py
# CLI demo with 4 built-in test cases

Notes

• No external API dependencies (pure Python, stdlib only)
• Defensive type checking throughout to handle malformed payloads
• Can be integrated into validate_fingerprint_data() in rustchain_v2_integrated_v2.2.1_rip200.py

---

Bounty: 50 RTC | Claimed by: kuanglaodi2-sudo

[github-actions]

Welcome to RustChain! Thanks for your first pull request.

Before we review, please make sure:

• Your PR has a BCOS-L1 or BCOS-L2 label
• New code files include an SPDX license header
• You've tested your changes against the live node

Bounty tiers: Micro (1-10 RTC) | Standard (20-50) | Major (75-100) | Critical (100-150)

A maintainer will review your PR soon. Thanks for contributing!

[Scottcjn]

Good security code in arch_cross_validation.py — architecture profiles, SIMD cross-checks, cache/thermal validation. Exactly what bounty #17 needs.

One fix needed: Your PR rewrites 69 unrelated files due to line ending changes (CRLF/LF). Please reset everything except the new file and resubmit with only arch_cross_validation.py.

Once cleaned up: merge + 50 RTC to your wallet.

[Scottcjn]

@kuanglaodi2-sudo — The real contribution here looks like node/arch_cross_validation.py (571 new lines), which is relevant to the bounty.

However, this PR also rewrites every other file in the repo — 29,470 additions and 28,663 deletions across 20+ files where the additions and deletions are identical (277+277, 579+579, etc.). This is typically caused by line-ending changes, whitespace reformatting, or re-encoding the entire file.

This is not mergeable as-is. A 30K-line diff that touches the entire codebase for what should be a single new module is a review and revert nightmare.

Please:

1. Create a new PR with only node/arch_cross_validation.py and any minimal integration changes
2. Do not touch files you didn't intentionally modify
3. Make sure your editor isn't reformatting the entire repo on save

The cross-validation concept is good — we want to verify it. But we can't review it when it's buried under 29K lines of noise.

— Scott