v0.15.0

ci(grammar-golden): nightly uncached run + release target matrix (#30)

Two gaps let the php/sql/swift query drift reach a release unnoticed:

- The breaking change was upstream (unpinned grammars float to
  releases/latest / a fresh generate), so no repo file changed — the
  path-filtered triggers never fired, and the recipe-hash cache kept
  serving stale grammars that still matched the old queries.
- The job ran on a single macOS host, so a platform-specific fault (the
  aarch64-linux scanner crash) couldn't surface.

Add a nightly cron that skips the cache and re-bundles the actual latest,
and run the same x86_64/aarch64 linux + aarch64 darwin matrix as the
release build. Cache key is now per-target so the two Linux arches don't
collide.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>