Trim the BLOCKED-on-green diagnostic in AGENTS.md to a recognition note plus a runbook #3174

🤖 Generated by the Agentic Engineer

Evidence

The green-but-BLOCKED diagnostic added in #3138 is 373 lines of AGENTS.md. That file is loaded
into context on every agent run against this repo, so the whole procedure is paid for on every run
while being needed only when someone actually meets that state. Two nits raised during the local
review round on #3138 were judged non-blocking there and deferred here rather than churning another
head on a docs PR.

Audience and problem

Every agent and every person working this repo pays the context cost; only the rare reader in the
blocked state gets the benefit.

What to change

1. Keep a short recognition note in AGENTS.md — what green-but-BLOCKED means here and the
   one-line tell that distinguishes it from an unresolved thread or a missing approval — and move the
   two shell procedures into a referenced runbook under docs/, read on demand.
2. State in the runbook that the bounded poll blocks are meant to run as a single script
   invocation. They are correct as written, but an agent that lifts a loop and unrolls it into
   per-iteration gh + sleep tool calls lands in the class the monorepo contract's Latency
   discipline forbids.

Acceptance criteria

• AGENTS.md keeps the recognition note and links the runbook; no procedure text is lost.
• The runbook carries the single-invocation statement for both poll blocks.
• Rough size: small.

Part of #3136