fix(host): 256-bin HE-LTF ingest end-to-end + latent offset bugs (#1005)

Audit of every ADR-018 consumer against live C6 HE20 frames (532B/256-bin):
- sensing-server + CLI calibrate parsers read n_subcarriers from one byte
  (256 decoded as 0) with stale seq/rssi offsets (rssi always 0 — latent,
  pre-existing, confirmed vs firmware csi_collector.c). Fixed to the real
  ADR-018 layout; n_subcarriers u8->u16; byte 18 surfaced as typed PpduType.
- sensing-server probe buffer 256B -> 2048B (532B datagram errored on Windows)
- per-node grid gate: lock densest (n_subcarriers, ppdu_type) grid, re-warm
  on upgrade, skip sparser minority frames — HT-64 never mixes into an
  HE-256 baseline window
- hardware parser: HE-aware bandwidth classification (256-FFT HE20 = 20MHz,
  was Bw160); PpduType/Adr018Flags re-exported
- verbatim live frames (532B HE-SU, 148B HT) embedded as regression fixtures
- archive python parser: bandwidth heuristic mirror fix

Live-validated: calibrate --tier he20 consumed 600x 256-bin frames into an
ADR-135 He20 baseline (242 tones) skipping 94 HT frames; sensing-server
shows node 12 active with real RSSI (-40dBm). 765 tests green across the
three crates; workspace check clean; Python proof PASS.

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

archive/v1/src/hardware/csi_extractor.py

@@ -221,11 +221,15 @@ class ESP32BinaryParser:
 
         snr = float(rssi - noise_floor)
         frequency = float(freq_mhz) * 1e6
-        bandwidth = 20e6  # default; could infer from n_subcarriers
 
-        if n_subcarriers <= 56:
+        # Bandwidth inference (issue #1005): HE-LTF uses a 4x denser tone
+        # grid than HT-LTF on the same channel width — an HE-SU frame with
+        # 256 bins (242 active HE20 tones) is a *20 MHz* capture, not 160.
+        if ppdu_byte in (1, 2, 3):  # HE-SU / HE-MU / HE-TB
+            bandwidth = 40e6 if (flags_byte & 0x01) or n_subcarriers > 256 else 20e6
+        elif n_subcarriers <= 64:  # ESP32 HT20 delivers the full 64-bin FFT
             bandwidth = 20e6
-        elif n_subcarriers <= 114:
+        elif n_subcarriers <= 128:
             bandwidth = 40e6
         elif n_subcarriers <= 242:
             bandwidth = 80e6