v0.22.2

v0.22.2 — SKILL.md content refresh + CHANGELOG backfill

Full content overhaul of .agents/.skills/audiolla/SKILL.md to bring it
back in sync with the actual API surface:

- 27+ stale endpoint paths corrected (visualize, restore, enhance,
  to_midi, noise-reduce, loudness-curve, hpss — all moved to namespaced /
  engine-in-path routes since v0.1.0).
- Dead `uvr-deecho-aggressive` engine slug removed.
- NEW sections: GET /v1/catalog as authoritative reference, Workflows
  (presets + pipeline), Async jobs, Output to presigned PUT URL.
- Engines table expanded from ~15 to ~25 entries.
- "When to use" + "When NOT to use" lists rewritten to cover ~30 newer
  capabilities + clarify the speech-features caveat.

Also: CHANGELOG.md backfilled with all 24 historical releases
(v0.1.0 → v0.22.2) — previously had only the v0.1.0 entry.

Docs only — no production code changes.