feat(sensing-server): route live frames through the governed StreamingEngine

Closes the live-trust-path gap (ADR-136 section 8, beyond-SOTA system review):
the running server fused live CSI with the bare MultistaticFuser, while the
privacy/provenance/witness control plane (ADR-135..146) only ever ran on
synthetic in-test frames. The privacy control plane was therefore bypassable
on the real path.

New engine_bridge module drives StreamingEngine::process_cycle from the
server's live NodeState map, reusing the existing NodeState -> MultiBandCsiFrame
conversion. It lazily wires each contributing node as a WorldGraph sensor
(idempotent), bounds belief growth via the retention cap, and forwards explicit
timestamps/calibration ids so the path stays deterministic and replayable.

Wired additively into both live ESP32/WiFi fusion sites in main.rs via a
split-borrow off the write guard, so person-count behavior is unchanged; the
latest BLAKE3 witness is stored on AppState. Every published belief now carries
evidence + model + calibration + privacy decision and a deterministic witness.

Adds wifi-densepose-engine/-worldgraph/-bfld/-geo deps. 6 new bridge tests
(witnessed belief with full provenance, cross-run determinism, idempotent node
registration, retention bound, privacy-mode propagation). sensing-server suite
430+128 green; workspace gate 2,904 passed / 0 failed.

https://claude.ai/code/session_01MjBucx95K4BuUxZi8NWwRH

v2/Cargo.lock

@@ -11079,9 +11079,13 @@ dependencies = [
  "tracing",
  "tracing-subscriber",
  "ureq 2.12.1",
+ "wifi-densepose-bfld",
+ "wifi-densepose-engine",
+ "wifi-densepose-geo 0.1.0",
  "wifi-densepose-hardware",
  "wifi-densepose-signal",
  "wifi-densepose-wifiscan",
+ "wifi-densepose-worldgraph 0.3.0",
 ]
 
 [[package]]