feat(pr41): Render Agnostic Output Layer (RAOL) — Halting Condition

[Copilot]

Implements PR #41: a hardware-agnostic graphics pipeline where pixel values are pure mathematical functions of a deterministic seed and style grammar. GPU is optional acceleration; the CPU reference path is always authoritative.

Core Pipeline

• Seed chain: seed(n) = SHA-256(seed(n-1) || n), anchored to the frozen invariant spec (PR feat: Autonomous Peano Sovereignty Layer (PR #39) #39)
• Pixel function: pixel(x, y, t, seed, style) → (r, g, b) — pure, integer-only, no float platform variance
• Dual-path execution: CPU always runs; GPU output accepted only when SHA-256(gpu_frame) == SHA-256(cpu_frame), otherwise silently rejected (gpu_rejected, verified=False)

from tools.render_agnostic.render.cpu_reference import compute_genesis_seed, load_style, render_frame, frame_sha256

seed = compute_genesis_seed(invariant_spec_hash)
style = load_style("cyberpunk_2026")  # hash-verified on load
frame = render_frame(seed, style, width=1920, height=1080, t=42)
print(frame_sha256(frame))  # identical on every platform, every Python version

New Artifacts

Path	Purpose
tools/render_agnostic/render/cpu_reference.py	Authoritative renderer — stdlib only, zero deps
tools/render_agnostic/render/gpu_accelerated.py	Optional GPU path with self-emptying on hash mismatch
tools/render_agnostic/render/hash_comparator.py	Per-frame FrameVerificationResult + append-only RenderLedger
tools/render_agnostic/grammar/schema.json	JSON Schema for style definitions
tools/render_agnostic/grammar/*.json	5 styles: cyberpunk_2026, photorealism, anime, pixel_art, minimal (each SHA-256 hash-addressed)
tools/render_agnostic/seeds/frame_manifest.jsonl	10-entry deterministic frame seed sequence
tools/render_agnostic/Dockerfile	Stateless, reproducible render environment
tests/test_pr41_render_agnostic.py	122 assertions across seed chain, pixel purity, dual-path, ledger integrity, cross-platform identity
.github/workflows/pr41-render-verification.yml	CI: ubuntu/windows/macos × Python 3.10–3.12, includes cross-platform hash identity check

Key Invariants Enforced by Tests

• cpu_reference.py imports only stdlib (AST-verified in test)
• All 5 style files have verified SHA-256 hashes; tamper detection is automatic on load
• gpu_rejected sets verified=False; RenderLedger.verify_integrity() flags any gpu_verified entry where cpu_hash != gpu_hash
• Frame manifest entries are sequential, seeds are 64-char hex, style IDs resolve to known grammar files

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