feat(adr-185): P3 MAT bindings (wifi_densepose.mat) + parity harness

Bind the ADR-024 MAT (Mass Casualty Assessment Tool) disaster-survivor
detection + START triage surface into the wheel behind a gated [mat]
extra / Cargo `mat` feature, mirroring the upstream disaster/ML gating.
Also adds the [sota] superset extra (aether+meridian+mat).

Surface (bound against the REAL code at HEAD, not the ADR wishlist):
- DisasterType (9 variants) / TriageStatus (5, START) enums
- DisasterConfig (builder-backed, continuous_monitoring forced off)
- DisasterResponse: initialize_event / add_zone / push_csi_data /
  scan_once / survivors / survivors_by_triage
- Survivor (id, triage_status, confidence, location, latest_vitals)
- VitalSignsReading (breathing/heartbeat rate, movement, confidence)
- ScanZone.rectangle / ScanZone.circle
push_csi_data + scan_once are GIL-released.

Honest deviations from ADR section 3.4 (documented in module header):
- ADR proposed adding a Rust-side sync scan_once() (section 11.3). That was
  UNNECESSARY: the public async start_scanning() runs exactly one
  scan_cycle and returns when continuous_monitoring == false. The binding
  forces that flag off and drives one cycle on a private current-thread
  tokio runtime -- NO change to wifi-densepose-mat.
- scan_cycle requires an active event + Active zone, which the ADR surface
  omitted; initialize_event + add_zone are bound as required additions.
- Survivor.vital_signs is a *history* in the real code; bound as
  Survivor.latest_vitals -> Optional[VitalSignsReading].
- DisasterType has 9 variants at HEAD (adds Landslide/MineCollapse/
  Industrial/TunnelCollapse); all bound.

Parity (section 4.1, release-blocking): committed fixture mat_input.json
(synthetic breathing-modulated CSI stream) -> native Rust reference
(tests/mat_parity.rs, drives DisasterResponse directly) locks
tests/golden/mat_result.sha256 over a canonical
`count=<K>;triage_priorities=<sorted>` string (survivor UUIDs/timestamps
excluded as non-deterministic); pytest (tests/test_mat.py) runs the same
stream through the binding and asserts the identical hash. Both detect
exactly 1 survivor, triage Delayed. Honest: synthetic fixture proves
binding==native path equality, NOT live detection accuracy.

Verified:
  cargo test --features mat --test mat_parity -> 2/2 pass
  maturin develop --features mat + pytest tests/test_mat.py -> 7/7 pass
  default cargo build clean, 0 mat/tokio refs in the default dep graph.

WHEEL-SIZE FINDING (ADR-185 section 9): default-features=false drops MAT's
`api` (axum) and `ruvector` features, but MAT still carries NON-optional
tokio (rt/sync/time), wifi-densepose-nn (ort/ONNX + reqwest/hyper),
rustfft, geo, ndarray. So a [mat] wheel exceeds the ADR-117 section 5.4
<=5 MB budget -- same leaf-crate-hoist follow-up as AETHER/MERIDIAN. The
default wheel is untouched (feature-gated).

python/Cargo.toml

@@ -36,6 +36,13 @@ aether = ["dep:wifi-densepose-sensing-server"]
 # below). `wifi-densepose-train` is depended on WITHOUT `tch-backend`,
 # so no libtorch is linked.
 meridian = ["dep:wifi-densepose-train", "dep:wifi-densepose-signal"]
+# ADR-185 P3 — MAT disaster-survivor detection. Mirrors the upstream
+# disaster/ML gating: bound only under this extra so the default wheel
+# never carries the detection stack. `tokio`/`geo` are pulled to drive a
+# single-shot scan (see the wheel-size note on the deps below).
+mat = ["dep:wifi-densepose-mat", "dep:tokio", "dep:geo"]
+# ADR-185 §3 — convenience superset: all three SOTA subsystems.
+sota = ["aether", "meridian", "mat"]
 
 [dependencies]
 # PyO3 with abi3-py310 — one compiled binary covers Python 3.10, 3.11,
@@ -97,6 +104,21 @@ wifi-densepose-sensing-server = { version = "0.3.0", path = "../v2/crates/wifi-d
 wifi-densepose-train = { version = "0.3.0", path = "../v2/crates/wifi-densepose-train", optional = true, default-features = false }
 wifi-densepose-signal = { version = "0.3.0", path = "../v2/crates/wifi-densepose-signal", optional = true, default-features = false }
 
+# ADR-185 P3 — MAT backing crate + the tokio/geo needed to drive one scan.
+#
+# HONEST WHEEL-SIZE NOTE (ADR-185 §9 / §1.3): `default-features = false`
+# drops MAT's `api` (axum) and `ruvector` features from the wheel, but MAT
+# still carries NON-optional `tokio` (rt/sync/time), `wifi-densepose-nn`
+# (which pulls `ort` / ONNX Runtime + reqwest/hyper), `rustfft`, `geo`,
+# and `ndarray`. So a `[mat]` wheel exceeds the ADR-117 §5.4 ≤5 MB budget
+# — same leaf-crate-hoist story as AETHER/MERIDIAN, gated the same way so
+# the DEFAULT wheel is untouched. `tokio` (rt+time) and `geo` are depended
+# on directly (version-matched to MAT) to build the single-shot scan
+# runtime and construct the event `geo::Point` in the binding.
+wifi-densepose-mat = { version = "0.3.0", path = "../v2/crates/wifi-densepose-mat", optional = true, default-features = false, features = ["std"] }
+tokio = { version = "1.35", features = ["rt", "time"], optional = true }
+geo = { version = "0.27", optional = true }
+
 [dev-dependencies]
 # ADR-185 §4.1 parity harness — SHA-256 the native-Rust reference
 # embedding and read the committed golden fixture.