fix: align stake and cash tools with current SDKs

[ADWilkinson]

Summary

• move stake commands to the current method-scoped dispute-protection SDK surface
• require and forward the exact payment method for prepared Peer Cash access policies
• update generated agent contracts, shipped skill guidance, dependencies, and release metadata for 0.4.0

Validation

• npm run check passed
• 230 tests passed across 21 files, including end-to-end coverage
• lint, typecheck, build, declaration bundles, and generated-contract checks passed
• npm audit reported zero vulnerabilities

Release ordering

This draft currently pins @zkp2p/cash@0.4.11-rc.3. It will move to the exact corrected Peer Cash candidate before this PR is marked ready.

[ADWilkinson]

Release ordering update: @zkp2p/cash 0.5.0 is now the stable latest (zkp2p/peer-cash#70). This branch should pin 0.5.0 rather than an rc before it is marked ready. The agents docs in zkp2p/zkp2p-clients#1801 describe the released 0.3.1 contract (stake chargeback-enabled, one-argument peer_cash_prepare_access_policy); update them when this ships.