Lockstep Player

Android prototype: music playback adapts to running pace (accelerometer + native DSP).

Docs (read these first):

Doc	Contents
SPECS.md	Product intent, MVP scope, libpasada DSP responsibilities, Oboe/JNI/MP3 FD assumptions, jukebox submodule role
DESIGN.md	Android architecture decisions, foreground run service, JNI/state machine (`init` / `play` / `pause` / `resume` / `stop` / …), open UI questions

Submodule: jukebox/.