feat: universal bitstream streaming — any input → any output
New crate: engine/ds-stream/
- Binary protocol: 16-byte header, typed frame/input enums
- Frame types: Pixels, Delta, Audio, Signal, Neural (0x01-0x43)
- Input types: Pointer, Key, Scroll, Gamepad, MIDI, BCI (0x01-0x90)
- WebSocket relay server (tokio + tungstenite)
- Source → receivers: frame broadcast
- Receivers → source: input routing
- Codec: encode/decode, XOR delta compression, RLE, convenience builders
- 17 unit tests, all passing
Streaming modes (stream-source.html):
1. Pixel mode: raw RGBA framebuffer (~28 MB/s)
2. Delta mode: XOR + RLE compression (~1-9 MB/s, 70-95% savings)
3. Signal mode: compact JSON signal diffs (~2 KB/s, 12000x reduction)
4. Neural mode: procedural SDF pixel generator (concept demo)
5. Audio channel: spring velocity→frequency synthesis
6. Multi-receiver: broadcast to all connected clients
Thin receiver client (stream-receiver.html, ~300 lines):
- Zero framework, zero build step
- Renders any incoming bitstream mode
- Local signal-diff renderer for signal mode
- AudioContext playback for audio frames
- Full input capture: click/drag, keyboard, scroll
- Per-channel bitstream bus visualization
DREAMSTACK.md: Phase 7 section with protocol spec