SD-301

[cross-model-adversarial] Testing strategy: cross-model adversarial. Different model family (GPT-4o or Gemini, not isolated Claude) writes tests from spec; implementation must pass tests it never influenced. CROSSMODEL-PROMPT.md moved from gitignored to docs/research/crossmodel-prompt.md (D3+ — agents do not enter D3+ unless Operator is watching). Different model family = genuinely different blind spots.

**STANDING**

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