v4 Phase 6: source-class axis, ARTIC absorbed, deletion-list close-out

SOURCE_CLASS in csd-engine: all 32 pitched models classified into five source classes (analog incl. the emulation fleet, fm, sampler, electromech, mechanical), each with an acoustic-membership grade; exported with sourceClassOf().

• Deletion list, item by item: ARTIC load-time patching TAKEN (12 genres now carry their envelope identity inline); STYLES presets TAKEN (zero live readers)

• Fixture drift: ZERO — 1047/1047 byte-stable through every edit, nothing regenerated. verify --no-cache PASS: matrix 63/63, validate full 5-seed 5/1/0, engine smoke.

• This closes the KERNEL-V4 strangler program: transforms, timeFeel, chordEvery, sampleEvents, and the source-class axis are dimensional infrastructure behind byte-stable adapters

▶ Play it: Ballroom Leviathan — a horn-and-piano genre that plays almost entirely sampled instruments https://stellate.app/?genre=bigband&seed=8117&path=814.14134,833.14167,795.14167&xdur=13.122

9256406 https://github.com/aboard-io/stellate/commit/92564065a50c733152a137c3cdfe74fd8d0e1b6d