v0.6.1

harletty-bridge 0.6.1

E-AC-3 stateful-decode fixes:
- chbwcod walk_state reset (per-frame aux-walk drift on
  coupling-strategy-update-mid-frame patterns).
- Legacy AC-3 backward-compat core accepted in raw Extractor
  (DD+ JOC streams that interleave [AC-3 core | E-AC-3 dep]).
- Bridge AC-3/dep pairing no longer loses queued cores on order
  variations (is_spatial() now correctly flips to true on dual-stream
  inputs delivered via the raw transport).

Adds an MKV-corpus regression suite (corpus_stream + compare_pcm
examples, Cavern PCM dotnet wrapper, driver scripts, cargo
integration test).