v1.2.0

### GPU Particle System
- GPU-driven pipeline: counter buffer, indirect draw, alive/dead index lists — zero dead particle processing
- `particle_lib.wgsl` auto-prepended to all compute shaders: shared structs, bindings, hash/rand, emit/alive helpers
- Alive/dead protocol: atomic emission claims, compact alive index rendering
- 3D curl noise flow field: 64x64x64 baked texture at `@group(1)`, `sample_flow_field()` helper
- Trail rendering: per-particle ring buffer, ribbon triangle strips with tapering width/alpha, separate indirect draw
- Spatial hash grid: 40x40 GPU 3-pass pipeline (count → prefix sum → scatter), neighbor query at `@group(3)`
- ParticleUniforms extended from 128 to 192 bytes (flow field + trail params)
- ParticleRenderUniforms extended from 32 to 48 bytes (frame_index + trail params)
- Particle UI panel: alive/max count with utilization bar, emit rate, burst, lifetime, speed, size, drag sliders, feature badges

### New Effects
- **Flux**: 30K particles following curl noise flow field, audio-reactive flow strength and speed
- **Ribbons**: 8K particles with flow field + 16-point trail ribbons, audio-reactive width/opacity
- **Chaos**: 50K particles tracing Lorenz/Rossler strange attractors with RK4 integration, 3D perspective projection, audio-reactive bifurcation parameters
- **Helix**: 20K charged particles spiraling via Lorentz force F=q(E+v×B), positive/negative charges, audio-reactive B_z and E fields
- **Murmuration**: 80K flocking particles with Vicsek model, spatial hash neighbor query, audio-reactive order↔disorder phase transition
- **Cymatics**: 40K particles forming Chladni nodal line patterns via gradient descent, audio frequency bands select mode numbers
- **Coral**: 50K particles tracing Turing-like organic growth patterns, hexagonal spots morphing to labyrinthine stripes

## Downloads

| Platform | File | Notes |
|----------|------|-------|
| **macOS** | `.dmg` | Universal binary (Apple Silicon + Intel) |
| **Linux x86_64** | `.tar.gz` | glibc 2.35+ (Ubuntu 22.04+, Debian 12+) |
| **Windows x64** | `.zip` | Windows 10+ |

## Getting started

**macOS**: Open the DMG, drag Phosphor.app to Applications (or run directly). Signed and notarized.

**Linux / Windows**: Extract, run `phosphor` from the extracted directory. The `assets/` folder must be next to the binary.

## Requirements

- **GPU**: Vulkan (Linux/Windows) or Metal (macOS)
- **Audio**: Built-in mic or line-in for audio-reactive visuals
- **NDI®** (optional): [NDI® SDK runtime](https://ndi.video) for network video output
- **Video playback** (optional): `ffmpeg` on PATH for media layers

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