feat(server): accuracy sprint 001 — Kalman tracker, multi-node fusion, eigenvalue counting
Wire three existing signal-crate components into the live sensing path:
Step 1 — Kalman Tracker (tracker_bridge.rs):
- PoseTracker from wifi-densepose-signal wired into all 5 mutable
derive_pose_from_sensing call sites
- Stable TrackId-based person IDs replace ephemeral 0-based indices
- Greedy Mahalanobis assignment with proper lifecycle transitions
(Tentative → Active → Lost → Terminated)
- Kalman-smoothed keypoint positions reduce frame-to-frame jitter
Step 2 — Multi-Node Fusion (multistatic_bridge.rs):
- MultistaticFuser replaces naive .sum() aggregation at both ESP32 paths
- Attention-weighted CSI fusion across nodes with cosine-similarity weights
- Fallback uses max (not sum) to avoid double-counting overlapping coverage
- Node positions configurable via --node-positions CLI arg
- Single-node passthrough preserved (min_nodes=1)
Step 3 — Eigenvalue Person Counting (field_model.rs upgrade):
- Full covariance matrix accumulation (replaces diagonal variance approx)
- True eigendecomposition via ndarray-linalg Eigh (Marcenko-Pastur threshold)
- estimate_occupancy() for runtime eigenvalue-based counting
- Calibration API: POST /calibration/start|stop, GET /calibration/status
- Graceful fallback to score_to_person_count when uncalibrated
New files: tracker_bridge.rs, multistatic_bridge.rs, field_bridge.rs
Modified: sensing-server main.rs, Cargo.toml; signal field_model.rs, Cargo.toml
Refs: .swarm/plans/accuracy-sprint-001.md
Co-Authored-By: claude-flow <ruv@ruv.net>
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