Adds the new SigmaStudio project export (Sigmastudio.zip, source
screenshot) alongside the existing project archives in Sigmastudio/,
rewrites docs/adau1701-sigmastudio-analysis.md for the 224-parameter
program (exclusive source mux replacing the old mixer, Bass Boost1/
SPhat1 dedicated blocks, unimplemented VU-meter readback), adds the
DigiRadioFinale figure/table to the manual, and adds a brief for the
iOS app side (active_source API shape, enhancement semantics change)
to hand to Cursor.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
