Engine-only install (4) README and ecosystem text for engine-only mode

[EdbertChan]

Summary

Describe ./install.sh --engine-only in README.md and docs/ecosystem.md so a
reader knows what the bare engine links, what it prunes, and that corpus
stays in git and refills as reflect and automate-me run. Depends on the
dead-hook prune slice having merged so the text matches shipped behavior.

Goal: A reader can find the engine-only mode from the README install
section and understand it from the ecosystem overview.
Motivation: The flag exists but nothing in the repo text mentions it.
Safety invariant: Text only; install.sh, tests, hooks, and skills are
untouched.
Effectiveness measurement: grep -c -- '--engine-only' README.md docs/ecosystem.md goes from 0 in each file to at least 1 in each.

Test Plan

Test Plan

• grep -q -- '--engine-only' README.md && grep -q -- '--engine-only' docs/ecosystem.md — Review claim: Both files mention the flag and nothing else changed.
  Review lane: proof
  Safety invariant: Read-only check.
  Effectiveness measurement: The grep counts are the measurement.
  Slice rationale: One focused proof for the text slice.
  Architectural effect: None; verification only.
  Goal: Prove both files mention the flag.
  Motivation: A text change is only reviewable when its presence is machine-checked.
  Alternative considerations: Manual reading was ruled out as non-deterministic.
  Implementation details: Run the two greps.
  Non-goals: No mutations.
  Layer: docs
  Feature state: active
  Acceptance criteria:

• Exits 0 only when both files mention the flag.

• bash scripts/scrub-handoff-artifacts.sh — Review claim: No ephemeral inter-task handoff files remain in the worktree before the merge gate.
  Review lane: cleanup
  Safety invariant: The scrub script only removes known handoff artifact names and never touches source, tests, or other repository files.
  Effectiveness measurement: The script exits non-zero if any handoff artifact remains.
  Slice rationale: Required terminal scrub for every implementation workflow.
  Architectural effect: None; hygiene only.
  Goal: Leave the branch free of handoff artifacts.
  Motivation: Handoff files must not reach the PR.
  Alternative considerations: Manual cleanup was ruled out as non-deterministic.
  Implementation details: Run scripts/scrub-handoff-artifacts.sh.
  Non-goals: No product edits.
  Layer: docs
  Feature state: active
  Acceptance criteria:

• bash scripts/scrub-handoff-artifacts.sh exits 0.

Revert Plan

Revert Plan

• Safe to revert? Yes
• Revert command: git revert <sha>
• Post-revert steps: None
• Data migration? No

---

Note

Low Risk
Documentation-only edits; no changes to install behavior, hooks, tests, or skills.

Overview
Documents the existing ./install.sh --engine-only flag so install docs and the ecosystem overview explain bare-engine installs without reading install.sh.

README adds an Engine-only mode subsection under Install: the flag links core engine skills, hooks, always-on rules, and the four cited product gates; prunes other corpus/product symlinks; points Claude at engine/CLAUDE.core.md instead of mined corpus/CLAUDE.learned.md; and notes that a full ./install.sh restores the stack while corpus remains in git and keeps growing from reflect / automate-me.

docs/ecosystem.md adds a matching Engine-only mode section, including ENGINE_CORE_PRODUCT_SKILLS, symlink pruning, the learned-rules / session-hygiene mirror behavior, and that corpus still accumulates mined output in git until a normal install relinks everything.

^{Reviewed by Cursor Bugbot for commit 014127f. Bugbot is set up for automated code reviews on this repo. Configure here.}

[cursor]

Bugbot couldn't run - usage limit reached

Bugbot is counted against Cursor usage for this user or team, and this run hit a usage or spend limit.

A user or team admin can review and increase usage limits in the Cursor dashboard.

(requestId: serverGenReqId_96a2d5fd-e2af-4a89-8af5-4d6517d6d95c)