Round 1 findings and fixes, all previously uncommitted:
- FXProcessor per-slot DSP history repair (HEAD does not compile without it)
- SynthVoice::getModulationValue, editor control-lock guard
- ExactCompare.h naming the deliberate exact float comparisons
- KnobLookAndFeel replacing the never-installed SerumLookAndFeel
- 55 first-party compiler warnings to 0
- AGENT.md renamed to AGENTS.md across Source/
- graft repository context graph and its hooks
- JANITOR_TASKS.md and UI_UX_AUDIT.md records
Introduce paramIds namespace with Oscillator struct and constexpr
arrays for envelope, LFO, FX, and macro parameter IDs. Replace the
scattered local const char* arrays in Engine and PluginEditor with
references to these shared definitions.
Return ModSource::Count from modSourceFromString for unknown strings
instead of silently mapping to Lfo1. Simplify isPerVoiceSource and
isPerVoiceTarget to range-based expressions.
biggy