v0.1.0

First release. Async client for the Yamaha Disklavier ENSPIRE local HTTP API, developed
against firmware 5.24.00 on an ENSPIRE PRO grand.

Added

• Disklavier client covering state, transport, volume, power, quiet mode, repeat and
  shuffle, library browsing, radio, and one-shot notifications.
• Typed models — StaticInfo, CurrentInfo, MasterState, PlaybackSnapshot, Song,
  Album, Playlist, RadioChannel — that convert the firmware's string-encoded numbers
  once, so callers never have to.
• async_notify, with async_snapshot_playback and async_restore_playback, for playing a
  one-shot notification and putting the piano back as it was.
• async_play_test_chord, which sounds a C major triad without touching the sequencer.
• Enumerations mirroring the firmware exactly: PowerStatus, PlaybackStatus, QuietMode,
  SongGroup, PlaylistGroup, Genre, GenreSelect, RepeatMode.
• PEP 561 py.typed marker, so type hints reach consumers.
• Browse methods translate the firmware's empty-library error envelope into the empty list
  it denotes, and DisklavierResponseError carries command and error_info attributes so
  the envelope errors that remain can be told apart without parsing messages.

Security

• Response bodies are read against a 1 MiB ceiling rather than without limit, so a hostile
  or broken device cannot stream the client's host out of memory.
• Redirects are refused. No endpoint the client calls legitimately redirects, and following
  one would hand the request to whatever host a spoofed device names.

Notes on firmware behaviour

These shaped the API and are documented in docs/enspire-api.md:

• Targets the versioned open API at /api/1.0/<command>, rather than the /api/api.php
  spelling of the same surface. The two were verified equivalent down to their error codes.
• There is no stop state — stop reports as pause at position zero, exposed as
  CurrentInfo.is_stopped.
• power_status has a transitional wakeup value lasting roughly twelve seconds, during
  which the piano ignores commands.
• Empty libraries arrive as an error envelope inside HTTP 200; the browse methods translate
  it back into an empty list.
• List responses switch between song_list and item_list depending on the group.
• State files can be read mid-rewrite and come back truncated, or carry a trailing NUL. Reads
  retry; the NUL is stripped rather than retried.
• Restoring playback stops first, because load_song changes the sequencer's selection
  without halting what is currently sounding.