harness

SwiftUI API usage rules for the Harness Monitor macOS app. Covers state wrappers (@State/@Binding/@Observable/@Bindable), view composition (structs over free functions, @ViewBuilder, modifier branches, ForEach identity), Picker/selection identity, button styles (.glass/.glassProminent, no .plain, ButtonStyle conformance, AccentColor), drag-and-drop (.draggable/.dropDestination, DragSession.Phase), navigation, lists, animations, layout, keyboard/focus, window management, commands, and anti-patterns. Invoke when writing or reviewing SwiftUI view structs, view state, selection controls, buttons, drag-drop interactions, navigation, or any SwiftUI-specific API usage in apps/harness-monitor/Sources.

SwiftUI/macOS UX rules covering accessibility (VoiceOver, Dynamic Type, contrast, target sizes), visual design (typography, 8pt spacing, color, dark mode, motion timing), interaction patterns (feedback, loading states, destructive actions, forms, truncation, notifications), and performance targets (60fps, launch time, scroll, memory). Invoke when writing or reviewing SwiftUI views, forms, lists, or any visible UI surface in apps/harness-monitor.

SwiftUI and Harness Monitor performance rules. Covers no DateFormatter/JSONEncoder/NumberFormatter allocation in view body, cached @MainActor formatters, no .repeatForever on always-visible views, no persisted state in .inspector/.searchable on first frame, no mirror-state loops for store-backed selection, no geometry feedback loops during animation, OSSignposter contract (io.harnessmonitor/perf/<scenario>), perf test env vars (HARNESS_MONITOR_KEEP_ANIMATIONS), and isolated worktree requirements for `mise run monitor:audit`. Invoke when writing or reviewing performance-sensitive SwiftUI code, animations, formatters, startup flow, persisted layout state, XCTest perf tests, or running Instruments audits in apps/harness-monitor.

macOS and iOS platform conventions plus XCUITest reliability rules. Covers menu bar ordering, window chrome (traffic lights, corner radius, minimum size), toolbar placements, sidebar width, Settings scene, dock/notifications, standard keyboard shortcuts (Cmd+N/O/S/W/Q/Z/F/,/M), iOS tab bar and safe areas, gestures, and XCUITest patterns (three-layer animation suppression, .firstMatch required, coordinate taps for non-hittable elements, single-launch test design, dragUp scroll helper, no Section-level accessibilityIdentifier). Invoke when writing or reviewing macOS window/menu/toolbar/settings code, platform-convention questions, iOS surfaces, or XCUITest tests in HarnessMonitorUITests.