feat: harden local runtime release boundary

[cloudsbeyond]

Summary

• fail closed when the local RPC server is asked to bind outside loopback
• return JSON-RPC 2.0 parse/request/method/params/internal error codes and reject bodies above 1 MiB
• add release-readiness contracts, L0-L4 project traceability, changelog, CI, package and dependency-security gates
• verify the packed package through capability-revision discovery and clean external consumer snapshots

Formal development chain

• L0 product scope remains unchanged in README / README.zh-CN.md / PRD.md
• L1/L2 additions: RPC transport contract and release-readiness contract
• L3: RPC server boundary enforcement and package/CI wiring
• L4: protocol, CLI, publication, packed consumer, Node 20/22 and security evidence

Validation

• pnpm test: 15 files, 116 tests passed
• pnpm typecheck: passed
• pnpm build: passed
• npm pack --dry-run --ignore-scripts: 21 files
• pnpm security:audit: no known production dependency vulnerabilities
• pnpm release:check: passed on Node 20 and Node 22
• clean packed-package consumer snapshots: 51 focused tests + typecheck and 8 focused tests + typecheck passed

Open owner gates

• real provider smoke with owner-managed credentials
• npm registry publication and tag approval
• production operation and any non-loopback/MCP exposure

Passing checks are local validation evidence and do not imply publication or product acceptance.

[cloudsbeyond]

Remote CI evidence:

• release-check (20): passed
• release-check (22): passed
• workflow run: https://github.com/cloudsbeyond/agent-runtime-services/actions/runs/29897706284

This is remote validation evidence only; real provider smoke, owner acceptance, merge, npm publication, and production operation remain separate gates.