Initial CLAP plugin scaffold for ES-5 encoder

Implements the full encoding pipeline for Expert Sleepers ES-5 with
ESX-8GT (gate) and ESX-8CV (CV) expanders as a native CLAP plugin.

Encoder logic ported from Expert Sleepers' MIT-licensed Pure Data
externals (https://github.com/expertsleepersltd/externals).

- ES-5 encoder: packs 6 × 8-bit header values into stereo 24-bit audio
- ESX-8GT encoder: 8 boolean gates → 1 byte
- ESX-8CV encoder: 8 × 12-bit CV values via 64-phase state machine
- 54 automatable parameters (6 header types + 48 gate/CV values)
- State save/load for preset support
- Builds on Linux (tested), macOS, and Windows

README.md

@@ -1,3 +1,63 @@
 # es5-clap
 
-Native CLAP plugin for Expert Sleepers ES-5/ESX-8CV/ESX-8GT encoder — Bitwig-friendly replacement for Silent Way
+Native [CLAP](https://cleveraudio.org/) plugin for encoding gate and CV data for the
+[Expert Sleepers ES-5](https://www.expert-sleepers.co.uk/es5.html) module via the
+[ES-9](https://www.expert-sleepers.co.uk/es9.html) ADAT output.
+Replaces Silent Way's ES-5 Controller for DAWs with CLAP support (Bitwig, REAPER, etc.).
+
+## Supported Hardware
+
+- **ES-5 mk3** — 6 expansion headers, encoded via stereo ADAT pair
+- **ESX-8GT** — 8 gate outputs per header (accent/velocity via PWM planned)
+- **ESX-8CV** — 8 CV outputs per header (12-bit DAC, ±10V range)
+
+## Building
+
+```bash
+cmake -B build -DCMAKE_BUILD_TYPE=Release
+cmake --build build -j$(nproc)
+```
+
+## Installation
+
+Copy the built plugin to your CLAP plugin directory:
+
+```bash
+# Linux
+cp build/es5-clap.clap ~/.clap/
+
+# macOS
+cp -r build/es5-clap.clap ~/Library/Audio/Plug-Ins/CLAP/
+```
+
+## Usage in Bitwig
+
+1. Add **ES-5 Encoder** as an audio effect on a track
+2. Route the track's audio output to the ES-9 ADAT channel pair feeding your ES-5
+   (default: ADAT channels 7/8, configurable via jumper on the ES-5 PCB)
+3. Set each header's type to match your connected expander (GT or CV)
+4. Automate the gate/CV parameters from Bitwig's modulation system
+
+### Parameter Layout
+
+| Parameter | ID | Range | Description |
+|---|---|---|---|
+| Header N Type | 1–6 | Off / GT / CV | Expander type on each header |
+| HN Ch1–8 | N01–N08 | 0.0–1.0 | Gate (>0.5 = on) or CV value |
+
+## Encoder Protocol
+
+Based on the [MIT-licensed Pure Data externals](https://github.com/expertsleepersltd/externals)
+by Expert Sleepers Ltd.
+
+The ES-5 receives a stereo audio stream where each 24-bit sample packs 3 bytes
+(L = headers 1–3, R = headers 4–6). Each byte drives one expansion header:
+
+- **ESX-8GT**: each bit = one gate output (8 gates per byte)
+- **ESX-8CV**: 12-bit values serialized via a 3-state, 64-phase protocol
+
+## License
+
+MIT — see [LICENSE](LICENSE).
+
+Encoder logic derived from Expert Sleepers Ltd MIT-licensed source code.