chore: publish 4.0.0-beta.2

[pacphi]

Why

4.0.0-beta.2 on the beta npm tag (master plan Decision 1). OpenCode returns.

In scope

Cut, publish, release notes.

Out of scope

Other tags.

Acceptance criteria

• npx @pacphi/agentic-kit@4.0.0-beta.2 --version prints the version
• latest and next are unchanged
• Release notes say which hosts are supported, which are not yet, the release each is planned for (Hermes: v5), and that users who rely on them should stay on 4.0.0-alpha.61

Dependencies

Blocked by: #385, #346, #348, #349, #350, #351, #352, #353, #354, #380

Blocks: #387

Plan

• Release: 4.0.0-beta.2
• Size: size:S · Workstream: ws:release
• Epic: chore: 4.0 release train (epic) #304
• Card: REL-B2 in the card inventory
• Sources: Master plan (docs(plans): v4 GA master plan, supersession ledger and v5 registers #290) Decisions 1 and 2

Verification

• npx @pacphi/agentic-kit@4.0.0-beta.2 --version