Fable Mode — Haiku (v3, agent-routed)

v3 change: the worker is a real agent definition (agents/fable-worker-haiku.md) invoked by name. Its system prompt carries the loop, the tightened verification rule, and the operational rules; this skill only routes.

If a task has one obvious correct approach and fits in a single pass, skip this loop and do it directly.

How to run it

1. Confirm fable-worker-haiku appears in the available agent types. If not, fall back to inline: spawn a general-purpose Haiku agent and pass it the rules verbatim from agents/fable-worker-haiku.md.
2. Spawn @fable-worker-haiku via the Task tool (subagent_type: "fable-worker-haiku"). Brief it with: the task, the exact output path(s), and the pass condition — name the check explicitly; Haiku gets no benefit of the doubt on verification.
3. Haiku is cheap: for independent sub-parts, fan out one worker per part and merge. Set a ceiling on concurrent workers.
4. Follow with @fable-verifier (a second Haiku is cheap; fresh eyes can't inherit the worker's blind spots) for anything that will be delivered without human review.
5. If a worker escalates ("needs synthesis"), re-route that part to fable-worker-sonnet rather than retrying Haiku with a louder prompt.
6. Mandatory delivery gate: before presenting the result to the user, invoke the double-check skill on the finished deliverable. If step 4's verifier already cold-checked the final document, double-check runs only the seam check — its own rules handle that. Do not skip the gate.