P0-1: Update subagent-preamble.md with Subagent Interaction Protocol

[Cho-Geer]

Parent Epic

#138 — Sub-Agent Question Propagation Fix

Phase 0 — Option A: Prompt + HANDOVER Protocol

Task

Add the Subagent Interaction Protocol section to .opencode/subagent-preamble.md:

## Subagent Interaction Protocol

You are running as a dispatched subagent. Do not call the built-in `question`
tool. It may not propagate to the parent/user session.

If user input is useful but not required:
1. Continue with the safest reversible assumption.
2. Record the question under `## Questions for User` in HANDOVER.md.
3. Record the assumption under `## Assumptions`.

If user input is required before a destructive, irreversible, or security-sensitive action:
1. Stop before the action.
2. Write the required question and options to HANDOVER.md.
3. Return an escalation result for Orchestrator to ask the user from the primary session.

Acceptance

• Generated dispatch prompts tell subagents not to call built-in question.
• Protocol covers both reversible and irreversible action cases.

Reference

docs/review/framework-refactor/sub-agent-question-propagation-issue.md §6 Option A

[Cho-Geer]

✅ Completed — Implemented by @Super-Admin via ses_115f2ce18ffex1FS1ucrajpeAM.

Added ### Step 0d: Subagent Interaction Protocol — MANDATORY section BEFORE Step 0e: Config Read Attestation in .opencode/subagent-preamble.md. Protocol covers:

• Reversible questions → HANDOVER.md ## Questions for User + ## Assumptions
• Irreversible/destructive questions → HANDOVER.md ## Blocked Actions Requiring User Approval + escalation