docs: host support guides for beta.2 #349

Why

Host guides change at beta.1 and beta.2 (ledger section E).

In scope

Update managed-tools.md and host-support.md: three hosts, the exception register, Hermes planned for v5.

Out of scope

The full docs pass.

Acceptance criteria

• The guides match the supported hosts

Dependencies

Blocked by: #348

Blocks: #383, #386

Plan

• Release: 4.0.0-beta.2
• Size: size:S · Workstream: ws:ga-readiness
• Epic: feat: project-scope P3, Codex and OpenCode project settings (epic) #298
• Card: P3-06 in the card inventory
• Sources: Supersession ledger (docs(plans): v4 GA master plan, supersession ledger and v5 registers #290) section E

Verification

• pnpm run lint:md