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>

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. */