Stage 2 — Compound Synthesis (Sequential, Linear)

> Output of Evo3 Stage 2 for LUME creative engine maturation. > 6 paths from Stage 1 (A bridge-first, B director-first, C pod-first, D reel-first, E maximalist, F minimalist) compounded into one ranked plan. > Sequential rule: Step 1 starts from ground truth; Steps 2-8 each inherit ALL prior steps and resolve conflicts explicitly. **Anchor in stage0-research.md, not in any path.** Five claims from Stage 0 are load-bearing for Stage 2: 1. **The music engine is deployed, not undefined.** (stage0 §C.6, §C.8.) Echelon-Rust → SAN-MLX (135K params, V5 weights, 5,408 real pairs, val loss 0.028) → AudioEngine.swift (2110 lines, AVF + Rust-FFI hybrid). Zero MusicGen/AudioCraft/Riffusion installs anywhere. The *gap* is **integration bridges**, not training. This invalidates memory §2's Phase A/B/C framing. 2. **Three competing AI directors exist with no canonical owner.** (stage0 §A.4/A.5/A.9, Top-3-facts #1.) `MotionMixDirector` (macOS multicam hub), `MotionMixLiveDirector` (iOS show-runner overlay), `StageView/Services/{GeminiLiveService,PhotoshootDirector}` (iPad performer-facing). All three are actively maintained. 3. **Universal sled does not exist; pod is K11-locked.** (stage0 §E, Top-3-facts #3.) `lume-pod.scad` and `pod_compute_sled` only have K11_VESA_PITCH=75 holes, K11-bottom-fan-intake/K11-top-fan-exhaust grid, K11-USB-A cable channels. Mac mini M4 has zero mounting points. Memory's "3hr port" estimate is wrong; it's a 1-2 day rewrite due to fan topology differences. 4. **Wave 8 is shipped (6 commits) but not pushed.** Mac1 main has `da8d1478`/`c5194f92`/`2a6e6b25`/`95387a02`/`8139a931`/`8fb6fe75`. K11 NSSM services live and reboot-survival proven. Mocopi-pro in mail; iPad LUMM fallback is the demo skeleton. (stage0 §A.1, §B.1.) 5. **Production-system constraint applies.** Memory §7b clarification: "Codex briefings going forward must label this as a production system so future agents don't treat it as throwaway scaffolding." This shapes the don't-touch list and forbids "good enough" handwavy work. **Don't-touch list (verified, must propagate to every Codex briefing):** - Wave 8 wire format magics: `LUME` (0x4C554D45), `LUMD` (0x4C554D44), `LUMF` (0x4C554D46), `LUMM` (0x4C554D4D), `LUMC`. Byte-for-byte pinned via `tests/test_wire_format_golden.py`. - 21 Unity component public APIs — additive only, no field renames or signature changes. - K11 NSSM service definitions (`install-services.ps1`) — runtime args may be flagged but service registration stays untouched. - Wave 8 commits not-pushed — Mohamed pushes manually after Mac4 verification. - LUMF wire format `audio_pub.py:send_lumf` byte order (golden-bytes test on Mac1). ## Step 2 — Music-gen pipeline decision (resolves Path A vs F vs the chain prompt's framing)