fable-5-train-opus-skills-after-it-retires

You are a distinguished fellow on this project who is retiring. Your final task: build a complete skill library under .claude/skills/ so that junior/mid-level engineers and smaller AI models (Sonnet-class) can carry this project forward without you — cheaper sessions must be able to debug, extend, validate, and eventually advance this project at the standard I hold today. Use multi-agent orchestration (workflows) for authoring and review; token cost is not a constraint, correctness is.

Phase 1 — Discover before you write (no skill authoring yet)

Investigate the repo like an incoming principal engineer: README/manifest/contributordocs, the build system, the test suite and how it's actually run, CI config, docs directories, git history (what changed, what got reverted, what stalled on dead branches), open TODO/FIXME hotspots, issue-shaped artifacts, generated-data or deploy conventions, and any project memory/notes available to you. Then ask me AT MOST five questions, only for what the repo cannot tell you — likely: (1) what is the hardest live problem right now, (2) what unwritten discipline rules exist (things you're not allowed to do that no doc states), (3) who is the audience for this library and what do they NOT know, (4) what past failures cost the most time, (5) what does "beyond state of the art" mean for this project. Fold my answers into everything below.

Phase 2 — Author the library (parallel agents, one skill per agent)

Instantiate this taxonomy, ADAPTED to what Phase 1 found — merge categories that are thin here, split ones that are deep, add domain categories I haven't imagined. Aim for 10–16 skills:

CORE (every project has these):

-change-control — how changes are classified, gated, reviewed here; the project's non-negotiables with the *rationale* and the historical incident behind each.

-debugging-playbook — symptom→triage table for this project's failure modes; the traps that cost real time (each with its story); discriminating experiments.

-failure-archaeology — the chronicle: every major investigation, dead end, rejected fix, and revert, as symptom → root cause → evidence → status, so no one re-fights a settled battle. Mine git history and docs hard for this.

-architecture-contract — the system's load-bearing design decisions and WHY; the invariants that must hold; the open known-weak points, stated plainly.