Integrate OBOL x402 payment rollout

[bussyjd]

Summary

• continue the OBOL Permit2 work from feat: add exact OBOL Permit2 buy-side path #339 on top of current main
• preserve full OBOL Permit2 payment payloads through buy-side auth, sidecar replay, delayed spend confirmation, and autorefill
• add OBOL token registry/payment metadata support while keeping USDC as the existing baseline
• add flows/flow-12-obol-payment.sh plus a RELEASE_SMOKE_INCLUDE_OBOL=true release-smoke hook for the OBOL payment path
• harden flow preflights so smoke runs use the active local stack kubeconfig instead of an ambient Kubernetes context

Supply-chain position

Depends on ObolNetwork/obol-infrastructure#2438, which is the infrastructure/facilitator PR that bumps ghcr.io/x402-rs/x402-facilitator to 1.4.7 and enables the EIP-2612 Permit2 path. This stack PR should land after that facilitator deployment work.

Upstream compatibility

x402-rs/x402-rs:main is at 1.4.7. The relevant upstream changes include DecimalU256 string amount handling and required contract-address validation; this branch signs string amount fields and validates token contracts before signing. flow-12 now validates the expected facilitator source/version when an X402_RS_DIR checkout is used.

Validation

• bash -n flows/lib.sh flows/flow-11-dual-stack.sh flows/flow-12-obol-payment.sh flows/release-smoke.sh
• python3 -m py_compile internal/embed/skills/buy-inference/scripts/buy.py
• go test -tags integration ./internal/openclaw -run TestIntegration_SellBuySidecar_OBOLPermit2 -count=0
• go test ./internal/x402 ./internal/x402/buyer ./internal/schemas ./internal/serviceoffercontroller ./cmd/obol -count=1
• live flows/flow-12-obol-payment.sh against a local stack with x402-rs facilitator 1.4.7: passed 7/7, including OBOL Permit2 buy-side auth, x402-buyer sidecar replay, three paid inference requests, and three successful settlements on a Base Sepolia Anvil fork with a fork-local OBOL-compatible token

[bussyjd]

Live OBOL Payment Validation

Validated on commit d85ab61.

Results:

• flows/flow-12-obol-payment.sh: PASS (7/7, flow_rc=0)
• x402-rs facilitator: 1.4.7 from x402-rs/x402-rs commit 0fe107c
• Chain context: Base Sepolia Anvil fork, advertised as eip155:84532
• Payment asset: fork-local OBOL-compatible ERC20Permit token
• Buyer probe advertised OBOL with transfer: permit2, EIP-712 Obol Network / 1, price 0.001 OBOL per request
• Buy path signed 3/3 payment authorizations
• x402-buyer sidecar consumed all auths: remaining=0, spent=3
• Settlement receipts: 3/3 successful (status=0x1)
• Balance assertion: buyer -0.003 OBOL, seller +0.003 OBOL
• Gas benchmark: 342519 total gas, 114173 avg gas/request

CI after the push is green: lint/test and CodeQL checks passed.