Echelon Layer 4 — Body-Time Loop Architecture

# Echelon Layer 4 — Body-Time Loop Architecture ## Crucible Stage 3: FORGE **Subject:** Body → Echelon → Music Closed Loop with 128D Temporal Closure **Date:** 2026-05-08 **Status:** FORGE PASS — ready for implementation review The CLAUDE.md description of the 128D layout is **partially wrong**. The authoritative source is `cc-brain/src/san/mod.rs:flatten_latent()` (lines 52–98). The actual Rust-side layout: **Consequence:** temporal data (tempo, phase, periodicity) ALREADY EXISTS in [69:72]. The gap is not that the data is absent — it is that `internal_tempo` is computed in `SimpleLatentUpdater.compute_dynamics()` via `detect_periodicity()` on norm history (autocorrelation of latent-space norm), NOT from a real autocorrelation of body periodicity. This estimate is noisy, has no confidence signal, and is not exposed back to iOS in a queryable way. The TEMPORAL SLOT PROBLEM is thus: 1. `internal_tempo` uses a proxy (norm variance) not body-kinematics autocorrelation 2. Tempo confidence [70] is currently repurposed as `phase` (not a confidence value) 3. No "body phase within current cycle" (normalized 0-1 position) distinct from `phase` 4. No swing amount in the canonical vector at all 5. No API to push an external tempo estimate (from Mocopi, audio analysis, tap tempo) into the Rust brain B. Add `push_temporal()` method on `EchelonCore` — passes through to LatentUpdater.