v0.8.4 - Audio and stage restoration fixes

Clone Driver corrects Sonic 2 instrument operator order, Simon Wai boss and
final-boss selections, and the prototype's percussion pitches. Hydrocity's PSG
percussion preserves the original tied-note rests, and the prototype Flying
Battery Act 1 lead and echo stay aligned across loops. CD invincibility music
continues through ring and other sound effects.

Power-up music follows the cartridge's tempo behavior: invincibility resets an
existing speed boost, shoes collected afterward speed up the music, and the
1-UP jingle plays normally before restoring the interrupted song's tempo.
Continuous sound effects retire when a new song starts.

Widescreen fixes cover Hydrocity's moving-wall redraw, Competition exit fades,
and Launch Base parallax at stage boundaries. Restored Hydrocity artwork uses
its prototype deformation without expanding the game's simulation area when
widescreen is disabled. Flying Battery retains native outdoor scenery and
transitions; Mushroom Hill and Lava Reef Act 1 gain the donor's earlier palettes.
Standalone Sonic 3 level select now starts a fresh stage after a checkpoint.
Original zone order skips the Mushroom Hill airship departure before Sandopolis.

Music choices include separate S&K/prototype mini-boss variants, Sonic 3 Knuckles
music, and the applicable final-boss themes in each game. The redundant Emerald
entry is hidden; existing selections are retained. Competition keeps its explicit
retail/prototype choices. Donor pickers accept .68k files and offer All files;
verified cartridge contents determine compatibility. SRAM diagnostic text is
readable on Windows.

All restoration and music replacements remain optional. No game assets are
included. See Music customization for donor requirements.