keyboard subsystem: Phase 4 cleanup, consolidation, rename (!41) · Merge requests · jedmund / synthesize

Created by: jedmund

Summary

Final phase of the keyboard subsystem rework: cleanup, consolidation, and renames that only made sense once every caller was on KeyboardContainer.

Rehome pitchRange helper. Moves pitchRange(startOctave:endOctave:) off the renderer and onto KeyboardContainerConfig. Updates 7 call sites (KeyboardCoordinator, PlayableKeyboardView, PlaygroundScreen, ScaleBuilderExercise, ModeExplorerView, ScaleExplorerView, plus shared usages).
Move KeyboardLabelMode to Models/. It's a model-layer enum that KeyboardPresentation already depended on; keeping it in the view-layer renderer file inverted the dependency graph.
Rename SynthKeyboardView → PianoKeys. Subviews renamed to WhiteKey / BlackKey (stay private). File moves from Views/Tools/PlayableKeyboard/ to Views/Components/KeyboardContainer/. Container docstring updated. File-top doc notes that future input surfaces (DrumPads, StepGrid, XYPad) will be peer renderers in sibling containers, not subtypes.

Stacks on top of phase 3 (ContentKeyboardPanel migration).

SynthKeyboardView / SynthWhiteKey / SynthBlackKey - zero hits app-wide
PianoKeys( - only in KeyboardContainer+Docked.swift and KeyboardContainer+Contained.swift
SynthKeyboardView.pitchRange - zero hits
.offset(y: inside keyboard-using callers - zero hits (Playground's remaining .offset(y:) uses are unrelated animations)
ScrollDisabler - only inside KeyboardContainer/ folder + its original definition in Views/Lesson/

Project builds for iOS simulator
Docked keyboard (PlayableKeyboard exercises) still renders and plays
Contained keyboards (VirtualSynth, ModMatrix, ScaleExplorer, ModeExplorer, ScaleBuilder, Playground, lesson content panel) still render and play
Overlays (step arcs, degree labels) still align with keys in all contexts