Harden x402 v2 payments and ClawHub skill metadata

[Abiorh001]

Summary

This hardens OmniClaw’s production x402 path and republishes the public OmniClaw CLI skill with correct OpenClaw/ClawHub metadata.

Changes

• Fix x402 v2 retry payloads to include the selected accepted payment requirements.
• Apply the same accepted handling to Circle Gateway nanopayments.
• Tighten seller-side verification so x402 v2 payments without valid accepted requirements are rejected.
• Make non-production strict settlement default safer for testing while preserving production/mainnet enforcement.
• Fix small nanopayment amount display so values like 0.00044 do not render as 0.00.
• Update tests for x402 exact, nanopayments, seller verification, facilitator flows, config, and routing.
• Harden the public OmniClaw CLI skill:
  • declares omniclaw-cli as required binary
  • declares OMNICLAW_SERVER_URL and OMNICLAW_TOKEN
  • declares OMNICLAW_TOKEN as primary env/secret
  • documents OMNICLAW_OWNER_TOKEN as optional and intentional only
  • adds explicit safety rules for omniclaw-cli serve --exec
  • adds OpenAI agent invocation policy
• Republish ClawHub skill as omniclaw@0.0.8.

Verification

• uv run ruff check src tests docs/omniclaw-cli-skill/scripts/generate_cli_reference.py
• uv run pytest -q
• ClawHub scan for omniclaw@0.0.8: clean