CURRENT VERSION VALIDATION — Ambient / Stutter / SELECT UI

PASS: tests/run_new_features.sh (exit 0): slice 11 fixtures; sidechain; transpose; swag; rosen; rosen FX 578 checks; chord integration 71411 cases; CZ preset/overload checks; four reverb models, bounded stress, tail silence and transitions; Room regression; backup 94; transpose 24; settings 53; MIDI 26; bootguard 91; looper 110.
PASS: dual-core suite: 5638 concurrent/serial PCM and state comparisons; worker deadlines and fallback; stack marker/guard; looper UI 24; voice policy 10368 fixtures; target C syntax with dual-core disabled/enabled.
Ambient impulse energy: 176436117 (test fixture); this is not a subjective audio-quality verdict.
Actual SELECT screen renders reviewed in docs/SELECT-PREVIEW.png.

UNCHANGED verified against previous Stage24 SELECT: eng_quad.c, loader sources, boot safety files and legacy golden fixtures. No legacy audio goldens regenerated. No device flashed here.
UNKNOWN: new target linker totals, JL assembly/linking, CPU0/CPU1 worst-case hardware timing, audible quality on FM1. Run target build and package checks before any installation.

Protected files compared: 24
