Add MIDI CC preset system for bundled device configurations:
- midi-cc-presets.js: listPresets/loadPreset/loadPresetFromFile API
- presets/polybrute.json: Arturia PolyBrute CC map
- Preset selector in quick controls bar and MIDI CC drawer
- File import button for loading JSON presets from disk
Bug fixes in a-app.js:
- Destroy IML instances before resizeMLP() to free WASM memory
- Fix randomiseWeights() call (was drawWeights())
- Fix thumbs-up to store rawParamValues instead of post-pipeline outputs
