add VST3 program list data

[erikgrahn13]

Summary

• add adapter-neutral built-in program collections with VST3-specific unit and program-list bindings
• implement IUnitInfo and IProgramListData across the controller and processor
• persist normal component state, selected programs, and modified program slots without generating preset files
• add opaque program payload support, validation, lifecycle-safe processor state handoff, documentation, examples, and CI coverage

Why

Singularity previously exposed ordinary processor parameter state, but did not provide a complete framework API for VST3 built-in program lists or program-list data. Plug-in developers now have a format-neutral model for built-in programs while the VST3 adapter owns the VST3-specific mapping and transport.

The processor state handoff also needed explicit lifecycle cleanup so a state queued immediately before termination could not survive a later reinitialization.

Developer impact

Developers can define stable ProgramCollection and BuiltInProgram entries, optionally attach opaque payload bytes, and map collections to VST3 units. Host-managed .vstpreset files remain host/installer concerns; Singularity does not generate preset files.

Plug-ins that do not define VST3 program-list bindings do not expose IProgramListData.

Validation

• full Debug and Release builds
• Steinberg VST3 validator: 47/47 for ExampleEffect and ExampleInstrument
• program-data test suites repeated in Debug and Release
• terminate/reinitialize lifecycle regression coverage
• git diff --check

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Preserve edited parameters during processing reconfiguration

When a host calls setupProcessing again after a block-size, sample-rate, or process-mode change, there is normally no pending program, so this condition sets applyParameters to true and reloads the selected program's factory snapshot. Any parameter edits or automation values accumulated since the program was selected are therefore overwritten merely by reconfiguring audio processing; distinguish initial setup from reconfiguration and reapply only the payload on later setup calls.

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