feat(acp): add Zed ACP Registry launcher package

[1xxalexx1]

Summary

• add the thin @nousresearch/hermes-agent npm launcher used by Zed's ACP Registry
• prefer the user's managed hermes-acp launcher so Hermes keeps its existing config, credentials, skills, memory, and model catalog
• fall back to a PATH launcher or uvx --from hermes-agent[acp] hermes-acp on POSIX systems
• include package tests and a publish dry-run-compatible package layout

Why

Zed's ACP Registry requires the package executable and the package name to line up. The existing Hermes PyPI distribution exposes hermes-acp as a secondary console script, so a registry uvx entry cannot launch it directly. This npm package provides the executable shape expected by the registry and leaves the ACP implementation in Hermes itself.

The package is intentionally a launcher, not a second Hermes runtime. Model enumeration, provider selection, authentication, tools, memory, and session behavior remain owned by Hermes ACP.

Validation

• npm test — passed
• node bin/hermes-agent.js --version — passed against Hermes 0.20.2
• npm pack --dry-run — passed

Publishing the package to npm and adding the corresponding ACP Registry entry are the follow-up release steps after this package is reviewed.

[1xxalexx1]

Prepared the companion ACP Registry manifest in draft PR agentclientprotocol/registry#529. That registry PR is intentionally draft until this launcher is published as @nousresearch/hermes-agent@0.20.2; the registry validator correctly rejects the unpublished npm package today.

[1xxalexx1]

Aligned the launcher package and companion registry manifest with current upstream Hermes 0.20.3. Local tarball install plus ACP smoke test passed: agent version 0.20.3, terminal auth advertised, 350 models, 3 modes. Registry PR remains draft only because the npm package is not published yet.