[yapishu]

Adds nockchain inspect and nockchain sign to the npm package, plus inspectSigningBundle and signSigningBundle library functions. Users save a bundle from the remote MCP, review it locally, and sign with a hidden zprv prompt or an explicit local key file. Recovery phrases require an explicit derivation path. The command requires interactive approval, creates a new file with mode 0600, and does not broadcast.

Validation reconstructs the payment plan from complete inputs and checks canonical encoding, commitments, existing signatures, maturity, recipients, change and fees, including small remainders assigned to fees. Existing signature verification can allow missing signatures without weakening its default threshold check. Network and tip fields remain indexed context, not a chain proof.

Implements the signing contract in https://github.com/SWPSCO/nockchain-rpc-server/pull/139. Sets the package version to 0.3.0 and includes the executable in the npm archive; package publication is separate.

Validation:

• Full suite: 31 tests pass; signing tests pass after the final schema-field checks.
• TypeScript and formatting checks pass.
• Five Rust-generated fixtures produce identical signed bytes and transaction IDs.
• Installed tarball CLI passes inspection, refusal without approval, hidden-key signing, mode 0600 and overwrite-refusal checks.
• CI checks the installed executable on Node 22 and 24.