C shipped dig.js + the flag but left the in-game input/mode hook to F (LANE_C_NOTES C2).
interior_mode.js (F-owned): aim at a userData.kind==='bin' fitting + press E -> createDig +
dig.open (per-bin seed binSeed(shop.seed,pos)); the dig owns the frame (renders dig.scene,
suppresses interior walk); WALK OUT/Esc closes back to the room; closed on interior exit.
Shell (index.html): ?dig=1 -> dig: opt; procity:digOpen releases pointer-lock (riffle is
cursor-driven); the unlock->leaveShop guard reads interiorMode.digActive so opening a bin
isn't read as walking out; canvas re-locks for interior walk after close.
Fresh-chromium smoke: E opens the riffle (seeded sleeves + prices render), WALK OUT closes
to the interior, leak-free (steady-state geo/tex flat over 3 open/close cycles), 0 console
errors. Flag off => no listener, dig stays null => byte-identical to v1 (prime law).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>