fix(sensing-server): canonicalize calibration frames to 56-tone grid (real HT40 fix)

Follow-up to the calibration deadlock fix. With the status gate unstuck,
maybe_feed_calibration reached feed_calibration, but a real ESP32 HT40 node
streams 128-wide amplitude frames while the single-link FieldModel is the
canonical 56-tone grid. LinkStats::update returned DimensionMismatch,
feed_calibration bubbled it, and maybe_feed_calibration swallowed it at debug
level — so frame_count stayed pinned at 0 on live hardware (presence/vitals,
which read the global history, were unaffected).

Resample each frame onto the model's canonical 56-tone grid via
HardwareNormalizer::resample_to_canonical before feeding — the same length-only
canonicalization the multistatic fusion path uses (#1170).

Pinned by maybe_feed_calibration_resamples_wide_frames_and_accumulates
(128-wide -> Collecting + count 1). sensing-server bin: 173 passed, 0 failed.

Co-Authored-By: claude-flow <ruv@ruv.net>

v2/crates/wifi-densepose-sensing-server/src/field_bridge.rs

@@ -7,12 +7,22 @@
 //! score-based heuristic in `score_to_person_count`.
 
 use std::collections::VecDeque;
+use std::sync::LazyLock;
+use wifi_densepose_signal::hardware_norm::HardwareNormalizer;
 use wifi_densepose_signal::ruvsense::field_model::{
     CalibrationStatus, FieldModel, FieldModelConfig,
 };
 
 use super::score_to_person_count;
 
+/// Length-only canonicalizer for calibration frames (issue #1170 pattern,
+/// shared with `multistatic_bridge`). Raw ESP32 amplitudes arrive at the
+/// hardware's native width (HT20 ≈ 64, HT40 ≈ 128/192); the FieldModel is
+/// configured for the canonical 56-tone grid, and `feed_calibration` rejects
+/// any other width with `DimensionMismatch`. Resampling here (default 56)
+/// lets real HT40 nodes actually calibrate instead of silently feeding nothing.
+static CALIB_NORMALIZER: LazyLock<HardwareNormalizer> = LazyLock::new(HardwareNormalizer::new);
+
 /// Number of recent frames to feed into perturbation extraction.
 const OCCUPANCY_WINDOW: usize = 50;
 
@@ -113,8 +123,13 @@ pub fn maybe_feed_calibration(field: &mut FieldModel, frame_history: &VecDeque<V
         return;
     }
     if let Some(latest) = frame_history.back() {
-        // Single-link observation: [1][n_subcarriers]
-        let observations = vec![latest.clone()];
+        // Resample the raw amplitude vector onto the FieldModel's canonical
+        // 56-tone grid before feeding. Real HT40 nodes stream 128-wide frames;
+        // feeding those raw made every `feed_calibration` fail DimensionMismatch
+        // (swallowed at debug level), pinning frame_count at 0 even after the
+        // status-gate deadlock was fixed. Single-link observation: [1][56].
+        let canonical = CALIB_NORMALIZER.resample_to_canonical(latest);
+        let observations = vec![canonical];
         if let Err(e) = field.feed_calibration(&observations) {
             tracing::debug!("FieldModel calibration feed: {e}");
         }
@@ -220,4 +235,32 @@ mod tests {
         maybe_feed_calibration(&mut field, &history);
         assert_eq!(field.calibration_frame_count(), 2);
     }
+
+    /// Regression (#1170 pattern): a real HT40 node streams 128-wide amplitude
+    /// frames, but the FieldModel is a 56-tone grid. Before canonicalization,
+    /// `feed_calibration` rejected every frame with DimensionMismatch (swallowed
+    /// at debug), so frame_count stayed 0 even with the deadlock fixed. The feed
+    /// must resample 128 → 56 and actually accumulate.
+    #[test]
+    fn maybe_feed_calibration_resamples_wide_frames_and_accumulates() {
+        let mut field = FieldModel::new(single_link_config()).expect("field model");
+
+        // 128-wide frame (HT40), NOT the model's 56 — would DimensionMismatch raw.
+        let wide = vec![0.5_f64; 128];
+        let mut history: VecDeque<Vec<f64>> = VecDeque::new();
+        history.push_back(wide);
+
+        maybe_feed_calibration(&mut field, &history);
+
+        assert_eq!(
+            field.status(),
+            CalibrationStatus::Collecting,
+            "128-wide frame must resample to 56 and be accepted"
+        );
+        assert_eq!(
+            field.calibration_frame_count(),
+            1,
+            "wide frame must accumulate, not be silently dropped"
+        );
+    }
 }