feat: Complete Rust port of WiFi-DensePose with modular crates

Major changes:
- Organized Python v1 implementation into v1/ subdirectory
- Created Rust workspace with 9 modular crates:
  - wifi-densepose-core: Core types, traits, errors
  - wifi-densepose-signal: CSI processing, phase sanitization, FFT
  - wifi-densepose-nn: Neural network inference (ONNX/Candle/tch)
  - wifi-densepose-api: Axum-based REST/WebSocket API
  - wifi-densepose-db: SQLx database layer
  - wifi-densepose-config: Configuration management
  - wifi-densepose-hardware: Hardware abstraction
  - wifi-densepose-wasm: WebAssembly bindings
  - wifi-densepose-cli: Command-line interface

Documentation:
- ADR-001: Workspace structure
- ADR-002: Signal processing library selection
- ADR-003: Neural network inference strategy
- DDD domain model with bounded contexts

Testing:
- 69 tests passing across all crates
- Signal processing: 45 tests
- Neural networks: 21 tests
- Core: 3 doc tests

Performance targets:
- 10x faster CSI processing (~0.5ms vs ~5ms)
- 5x lower memory usage (~100MB vs ~500MB)
- WASM support for browser deployment

rust-port/wifi-densepose-rs/docs/ddd/domain-model.md

@@ -0,0 +1,114 @@
+# Domain-Driven Design: WiFi-DensePose Domain Model
+
+## Bounded Contexts
+
+### 1. Signal Domain
+**Purpose**: Raw CSI data acquisition and preprocessing
+
+**Aggregates**:
+- `CsiFrame`: Raw CSI measurement from WiFi hardware
+- `ProcessedSignal`: Cleaned and feature-extracted signal
+
+**Value Objects**:
+- `Amplitude`: Signal strength measurements
+- `Phase`: Phase angle measurements
+- `SubcarrierData`: Per-subcarrier information
+- `Timestamp`: Measurement timing
+
+**Domain Services**:
+- `CsiProcessor`: Preprocesses raw CSI data
+- `PhaseSanitizer`: Unwraps and cleans phase data
+- `FeatureExtractor`: Extracts signal features
+
+### 2. Pose Domain
+**Purpose**: Human pose estimation from processed signals
+
+**Aggregates**:
+- `PoseEstimate`: Complete DensePose output
+- `InferenceSession`: Neural network session state
+
+**Value Objects**:
+- `BodyPart`: Labeled body segment (torso, arms, legs, etc.)
+- `UVCoordinate`: Surface mapping coordinate
+- `Keypoint`: Body joint position
+- `Confidence`: Prediction confidence score
+
+**Domain Services**:
+- `ModalityTranslator`: CSI → visual feature translation
+- `DensePoseHead`: Body part segmentation and UV regression
+
+### 3. Streaming Domain
+**Purpose**: Real-time data delivery to clients
+
+**Aggregates**:
+- `Session`: Client connection with history
+- `StreamConfig`: Client streaming preferences
+
+**Value Objects**:
+- `WebSocketMessage`: Typed message payload
+- `ConnectionState`: Active/idle/disconnected
+
+**Domain Services**:
+- `StreamManager`: Manages client connections
+- `BroadcastService`: Pushes updates to subscribers
+
+### 4. Storage Domain
+**Purpose**: Persistence and retrieval
+
+**Aggregates**:
+- `Recording`: Captured CSI session
+- `ModelArtifact`: Neural network weights
+
+**Repositories**:
+- `SessionRepository`: Session CRUD operations
+- `RecordingRepository`: Recording storage
+- `ModelRepository`: Model management
+
+### 5. Hardware Domain
+**Purpose**: Physical device management
+
+**Aggregates**:
+- `Device`: WiFi router/receiver
+- `Antenna`: Individual antenna configuration
+
+**Domain Services**:
+- `DeviceManager`: Device discovery and control
+- `CsiExtractor`: Raw CSI extraction
+
+## Context Map
+
+```
+┌─────────────────────────────────────────────────────────────┐
+│                      WiFi-DensePose                         │
+├─────────────────────────────────────────────────────────────┤
+│                                                             │
+│  ┌──────────────┐     ┌──────────────┐     ┌─────────────┐ │
+│  │   Hardware   │────▶│    Signal    │────▶│    Pose     │ │
+│  │   Domain     │     │    Domain    │     │   Domain    │ │
+│  └──────────────┘     └──────────────┘     └─────────────┘ │
+│         │                    │                    │        │
+│         │                    │                    │        │
+│         ▼                    ▼                    ▼        │
+│  ┌──────────────────────────────────────────────────────┐  │
+│  │                   Storage Domain                      │  │
+│  └──────────────────────────────────────────────────────┘  │
+│         │                    │                    │        │
+│         ▼                    ▼                    ▼        │
+│  ┌──────────────────────────────────────────────────────┐  │
+│  │                  Streaming Domain                     │  │
+│  └──────────────────────────────────────────────────────┘  │
+│                                                             │
+└─────────────────────────────────────────────────────────────┘
+```
+
+## Ubiquitous Language
+
+| Term | Definition |
+|------|------------|
+| CSI | Channel State Information - WiFi signal properties |
+| Subcarrier | Individual frequency component in OFDM |
+| Phase Unwrapping | Correcting 2π phase discontinuities |
+| DensePose | Dense human pose estimation with UV mapping |
+| Modality Translation | Converting CSI features to visual features |
+| Body Part | One of 15 labeled human body segments |
+| UV Mapping | 2D surface parameterization of 3D body |