v0.3.9

### Added
- **Three new particle effects** — Veil (flowing silk curtain with displacement field physics), Nova (fireworks with burst emission and gravity), Vortex (black hole with 1/r² orbital mechanics, accretion disk, and polar jets)
- **Keyboard hints in status bar** — "D toggle overlay · F fullscreen" shown when overlay is hidden
- **Auto-show panels** — overlay panels fade in with 2s delay + 1s alpha fade on first launch, bypassed by manual toggle
- BPM convergence tests at 90/120/140/170/200/230 BPM with extracted `run_bpm_convergence_test` helper

### Changed
- Rename Settings panel to Global
- Replace CVD themes (Deuteranopia/Protanopia/Tritanopia) with visually distinct VJ themes (Midnight/Ember/Neon)

### Fixes
- Show actual dlopen error messages in NDI diagnostics panel (exposes quarantine, signature, and architecture mismatch issues); upgrade failed-path logging to `warn` level; add macOS troubleshooting tips for quarantine removal and ad-hoc signing

## 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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NDI® is a registered trademark of Vizrt NDI AB.