v2.2.1 — Gemini array fix + use-cases

Fixed

• Gemini provider (#64): array JSON schemas now translate to Type.ARRAY with translated items. Previously toGemini() had no array case, so array schemas fell through to the string default and Gemini returned a comma-joined string instead of a JSON array — breaking any structured array output (extraction, the boundary judge) on the Google provider. Adds regression tests.
• examples/compose.ts (#64): the reducePattern callback signature is (acc, item), not an index.

Added

• examples/use-cases/ (#64) — six runnable real-world scenarios (support triage · code-review gate · secret-safe logs · batch digest · nightly report · a live-LLM A/B) that show what the runtime adds over a plain skill/prompt.