feat: ADR-063/064 mmWave sensor fusion + multimodal ambient intelligence (#269)

* docs: ADR-063 mmWave sensor fusion with WiFi CSI

60 GHz mmWave radar (Seeed MR60BHA2, HLK-LD2410/LD2450) fusion
with WiFi CSI for dual-confirm fall detection, clinical-grade
vitals, and self-calibrating CSI pipeline.

Covers auto-detection, 6 supported sensors, Kalman fusion,
extended 48-byte vitals packet, RuVector/RuvSense integration
points, and 6-phase implementation plan.

Based on live hardware capture from ESP32-C6 + MR60BHA2 on COM4.

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

* feat(firmware): ADR-063 mmWave sensor fusion — full implementation

Phase 1-2 of ADR-063:

mmwave_sensor.c/h:
- MR60BHA2 UART parser (60 GHz: HR, BR, presence, distance)
- LD2410 UART parser (24 GHz: presence, distance)
- Auto-detection: probes UART for known frame headers at boot
- Mock generator for QEMU testing (synthetic HR 72±2, BR 16±1)
- Capability flag registration per sensor type

edge_processing.c/h:
- 48-byte fused vitals packet (magic 0xC5110004)
- Kalman-style fusion: mmWave 80% + CSI 20% when both available
- Automatic fallback to CSI-only 32-byte packet when no mmWave
- Dual presence flag (Bit3 = mmwave_present)

main.c:
- mmwave_sensor_init() called at boot with auto-detect
- Status logged in startup banner

Fuzz stubs updated for mmwave_sensor API.
Build verified: QEMU mock build passes.

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

* fix(firmware): correct MR60BHA2 + LD2410 UART protocols (ADR-063)

MR60BHA2: SOF=0x01 (not 0x5359), XOR+NOT checksums on header and
data, frame types 0x0A14 (BR), 0x0A15 (HR), 0x0A16 (distance),
0x0F09 (presence). Based on Seeed Arduino library research.

LD2410: 256000 baud (not 115200), 0xAA report head marker,
target state byte at offset 2 (after data_type + head_marker).

Auto-detect: probes MR60 at 115200 first, then LD2410 at 256000.
Sets final baud rate after detection.

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

* feat: ADR-063 Phase 6 server-side mmWave + CSI fusion bridge

Python script reads both serial ports simultaneously:
- COM4 (ESP32-C6 + MR60BHA2): parses ESPHome debug output for HR, BR, presence, distance
- COM7 (ESP32-S3): reads CSI edge processing frames

Kalman-style fusion: mmWave 80% + CSI 20% for vitals, OR gate for presence.

Verified on real hardware: mmWave HR=75bpm, BR=25/min at 52cm range,
CSI frames flowing concurrently. Both sensors live for 30 seconds.

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

* docs: ADR-064 multimodal ambient intelligence roadmap

25+ applications across 4 tiers from practical to exotic:
- Tier 1 (build now): zero-FP fall detection, sleep monitoring,
  occupancy HVAC, baby breathing, bathroom safety
- Tier 2 (research): gait analysis, stress detection, gesture
  control, respiratory screening, multi-room activity
- Tier 3 (frontier): cardiac arrhythmia, RF tomography, sign
  language, cognitive load, swarm sensing
- Tier 4 (exotic): emotion contagion, lucid dreaming, plant
  monitoring, pet behavior

Priority matrix with effort estimates. All P0-P1 items work with
existing hardware (ESP32-S3 + MR60BHA2 + BH1750).

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

* fix(ci): add ESP_ERR_NOT_FOUND to fuzz stubs

mmwave_sensor stub returns ESP_ERR_NOT_FOUND which wasn't
defined in the minimal esp_stubs.h for host-based fuzz testing.

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

firmware/esp32-csi-node/main/edge_processing.h

@@ -106,6 +106,35 @@ typedef struct __attribute__((packed)) {
 
 _Static_assert(sizeof(edge_vitals_pkt_t) == 32, "vitals packet must be 32 bytes");
 
+/* ---- ADR-063: Fused vitals packet (48 bytes, wire format) ---- */
+#define EDGE_FUSED_MAGIC  0xC5110004  /**< Fused vitals packet magic. */
+
+typedef struct __attribute__((packed)) {
+    /* First 32 bytes match edge_vitals_pkt_t layout */
+    uint32_t magic;          /**< EDGE_FUSED_MAGIC = 0xC5110004. */
+    uint8_t  node_id;
+    uint8_t  flags;          /**< Bit0=presence, Bit1=fall, Bit2=motion, Bit3=mmwave_present. */
+    uint16_t breathing_rate; /**< Fused BPM * 100 (CSI + mmWave Kalman). */
+    uint32_t heartrate;      /**< Fused BPM * 10000. */
+    int8_t   rssi;
+    uint8_t  n_persons;
+    uint8_t  mmwave_type;    /**< mmwave_type_t enum. */
+    uint8_t  fusion_confidence; /**< 0-100 fusion quality score. */
+    float    motion_energy;
+    float    presence_score;
+    uint32_t timestamp_ms;
+    /* mmWave extension (16 bytes) */
+    float    mmwave_hr_bpm;  /**< Raw mmWave heart rate. */
+    float    mmwave_br_bpm;  /**< Raw mmWave breathing rate. */
+    float    mmwave_distance;/**< Distance to nearest target (cm). */
+    uint8_t  mmwave_targets; /**< Target count from mmWave. */
+    uint8_t  mmwave_confidence; /**< mmWave signal quality 0-100. */
+    uint16_t reserved3;
+    uint32_t reserved4;     /**< Pad to 48 bytes for alignment. */
+} edge_fused_vitals_pkt_t;
+
+_Static_assert(sizeof(edge_fused_vitals_pkt_t) == 48, "fused vitals must be 48 bytes");
+
 /* ---- Edge configuration (from NVS) ---- */
 typedef struct {
     uint8_t  tier;           /**< Processing tier: 0=raw, 1=basic, 2=full. */