feat: Add hardware requirement notice to README, additional Three.js viz components

Add prominent hardware requirements table at top of README documenting
the three paths to real CSI data (ESP32, research NIC, commodity WiFi).
Include remaining Three.js visualization components for dashboard.

https://claude.ai/code/session_01Ki7pvEZtJDvqJkmyn6B714

README.md

@@ -1,5 +1,17 @@
 # WiFi DensePose
 
+> **Hardware Required:** This system processes real WiFi Channel State Information (CSI) data. To capture live CSI you need one of:
+>
+> | Option | Hardware | Cost | Capabilities |
+> |--------|----------|------|-------------|
+> | **ESP32 Mesh** (recommended) | 3-6x ESP32-S3 boards + consumer WiFi router | ~$54 | Presence, motion, respiration detection |
+> | **Research NIC** | Intel 5300 or Atheros AR9580 (discontinued) | ~$50-100 | Full CSI with 3x3 MIMO |
+> | **Commodity WiFi** | Any Linux laptop with WiFi | $0 | Presence and coarse motion only (RSSI-based) |
+>
+> Without CSI-capable hardware, you can verify the signal processing pipeline using the included deterministic reference signal: `python v1/data/proof/verify.py`
+>
+> See [docs/adr/ADR-012-esp32-csi-sensor-mesh.md](docs/adr/ADR-012-esp32-csi-sensor-mesh.md) for the ESP32 setup guide and [docs/adr/ADR-013-feature-level-sensing-commodity-gear.md](docs/adr/ADR-013-feature-level-sensing-commodity-gear.md) for the zero-cost RSSI path.
+
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