trillium-compression-v0.3.0

Changed (breaking)

• Default brotli level lowered from Level::Default (quality 11) to
  Level::Precise(4), matching common reverse-proxy transport defaults.
  Quality 11 is roughly 100× slower than quality 4 for marginal size gains
  and is unsuitable for the response hot path. Callers that want maximum
  compression can opt back in with with_brotli_level(Level::Best).
• Encoders are now constructed with with_quality(...) instead of new()
  so the configured level is actually applied per request.

Added

• with_brotli_level, with_gzip_level, with_zstd_level for per-algorithm
  level configuration. Level is re-exported from async-compression.

Fixed

• Skip compression when the response already has Content-Encoding set.
  Previously the middleware would re-compress precompressed sidecar
  responses, producing invalid output and explosive memory use under any
  concurrency.
• Skip compression for content types that are already compressed (image
  binary formats, video/, audio/, web fonts, common archive formats).
  image/svg+xml and application/wasm are intentionally still compressed.