security: fail closed on untrusted payment targets (AIFINP-62)

[coinsecuritiescompany]

Outcome

Blocks untrusted 402 metadata before wallet signing across Node, MCP and Python. Solana payment signing is quarantined because deployed contract v0.5.3 is replay-unsafe.

Node SDK 1.7.1

• binds EVM chain, splitter, runtime codehash, v1.2 ABI, treasury/owner, fee policy, provider merchant and validity window
• rejects RPC error, wrong chain/codehash, EOA/empty code, stale entry, target/version/merchant/royalty/fee mismatch
• removes dynamic ABI detection, RPC fallback and all v1.1 payMatic signing
• enables only Polygon v1.2 Safe governance; quarantines Base/Optimism/Unichain/BOT/XRPL EVM
• disables standard x402 EIP-3009 signing until asset/payTo/domain/decimals have a signed registry
• corrects the legacy Solana builder to the deployed v0.5.3 IDL for audit evidence, but makes it unreachable from the wallet path
• always rejects Solana payment signing with solana_route_disabled_pending_v0_6_upgrade until replay-safe contract PRs #1 and #2 are deployed and bound to a verified ProgramData hash/upgrade authority

MCP 1.4.1

• builds against this PR's local SDK in CI
• declares tweetnacl and bs58 directly (previous build depended on transitive hoisting)
• inherits the same EVM validation and Solana quarantine

Python 1.3.1

• mirrors exact Polygon quote/runtime validation and removes v1.1/treasury fallbacks
• mirrors Solana metadata validation but blocks the signing route before RPC/transaction construction

Validation performed

• Node TypeScript build after quarantine: passed
• Node focused payment suite after quarantine: 38 passed
• Node offline suite before Solana follow-ups: 81 passed
• Node publish tarball: passed
• MCP build against published dependency: passed
• MCP build against local Node 1.7.1: passed
• MCP bin syntax + tarball: passed
• Python compileall after quarantine: passed
• version gate: Node 1.7.0→1.7.1, MCP 1.4.0→1.4.1, Python 1.3.0→1.3.1

Validation not performed locally

• The environment rejected the post-Solana full Node-suite rerun after reaching its execution usage limit. The 38 payment-critical tests are post-patch; 81/81 is pre-follow-up evidence.
• Python pytest dependencies could not be installed for the same reason. CI must run the existing Python suite plus 30 target-validation tests.
• This PR must not be marked ready if either CI job is red.

Explicit remaining acceptance gaps

• Jira requires a signed registry/signer policy. No root public key, threshold, rotation procedure or signed registry document exists in connected sources.
• Solana v0.6.0 must compile/test, pass independent review, be upgraded by the verified authority, and publish ProgramData hash + generated IDL before SDK work can replace the quarantined v0.5 builder.
• Standard x402 signing and remote registry updates remain disabled.

Latest GitHub commit: 2215372337e5d1437bf90a3b342d96c15e83110b.
Local equivalent: 6f9ae92.

Partially satisfies AIFINP-62 pending signed-root policy, CI, contract deployment evidence, and reviewer approval.