Harden buyer payment control semantics

[Abiorh001]

Summary

• remove internal whitepaper drafts and research planning docs from the open-source product repo after moving them to the separate paper workspace
• bind payment-intent authorization to exact buyer-side execution parameters with a keyed digest
• preserve outcome-unknown payments for settlement review and resolve linked intents/reservations on reconciliation
• add hash-chained buyer audit events with scoped trace access and verification helpers
• audit intent success, failure, cancellation, review approval, settlement-check, and settlement-resolution paths
• make payment execution retries opt-in safe instead of string-matching generic timeout errors
• add focused buyer payment control and wallet ambiguity tests

Verification

• uv run pre-commit run --files src/omniclaw/audit.py src/omniclaw/client.py src/omniclaw/core/authorization.py src/omniclaw/intents/intent_facade.py src/omniclaw/resilience/retry.py src/omniclaw/wallet/service.py tests/test_buyer_payment_control.py tests/test_wallet_service.py
• uv run pre-commit run --files src/omniclaw/audit.py src/omniclaw/client.py tests/test_buyer_payment_control.py
• uv run pytest tests/test_buyer_payment_control.py tests/test_wallet_service.py tests/test_intent_transitions.py tests/test_payment_intents.py tests/test_intent_lifecycle.py tests/test_idempotency.py tests/test_x402_idempotency.py tests/test_reservation_integrity.py
• uv run ruff check src/ tests/test_buyer_payment_control.py tests/test_wallet_service.py
• uv run ruff format --check src/ tests/test_buyer_payment_control.py tests/test_wallet_service.py
• rg -n "RESEARCH_EVIDENCE_MATRIX|RESEARCH_THESIS_AND_OUTLINE|whitepaper v2|research-grade|preprint|arXiv|research paper" docs README.md .github pyproject.toml || true

[Abiorh001]

Refreshing PR metadata after branch update.