feat(a11y): semantic colour system (#21 phase 1)

Replaces every hard-coded colour with semantic asset colours that adapt to
light, dark, and Increase Contrast. Dark mode stays locked, so this is a
pure refactor: the audit reports the same findings before and after.

The accent is now blue rather than cyan, per the tech/DNS theme.

Why custom values rather than the system palette: every system colour
fails WCAG AA in light mode. Measured on white — systemYellow 1.51:1,
systemOrange 2.20:1, systemGreen 2.22:1, systemCyan 2.54:1, systemRed
3.55:1. All of them pass in dark mode, which is why the dark-locked app
looked fine, and why unlocking light mode was never a matter of deleting
.preferredColorScheme(.dark). Every new value clears 4.5:1 as text on its
page, its card, and its own 16% badge tint — the way AppStatusBadgeView
actually draws it.

The accent needed splitting in two. As text on a dark background it must
be light; as a fill behind a white label it must be dark. #4DA3FF reads
8.00:1 as text on black but 2.63:1 behind white text, so StatusInfo /
AccentColor cover the foreground role and AccentFill covers
.borderedProminent. AppOnAccent is the label colour for a solid fill and
flips by scheme.

Colours live in Shared/Colors.xcassets rather than the app catalog: the
Shared folder is already a synchronized group in all three targets, so
the widget and share extension pick the palette up with no project-file
surgery. AccentColor stays in the app catalog as the global tint — and is
now actually defined, having been an empty colorset that silently left
system controls rendering in stock blue while custom chrome used cyan.

Two deliberate visual changes: orange folds into StatusWarning and pink
into StatusCritical. They encoded the same severity as the colours they
now share, and both sites also carry a text label.

Audit findings drop 15 to 14, and one of the originals turned out to be
a phantom: the Inspect contrast failure was the Run button in its
disabled state, which WCAG 1.4.3 exempts. testInspectScreen now types a
domain first so the audit measures an enabled control. Findings also
carry the offending element now, so the remaining clipped-text items name
themselves ("No Portfolio Yet", "Search domains") instead of being
anonymous.

1 files changed, 21 insertions, 21 deletions

diff --git a/DomainDig/DomainDigUI.swift b/DomainDig/DomainDigUI.swift
index 272c678..9c63e73 100644
--- a/DomainDig/DomainDigUI.swift
+++ b/DomainDig/DomainDigUI.swift
@@ -92,48 +92,48 @@ enum AppStatusFactory {
     static func availability(_ status: DomainAvailabilityStatus?) -> AppStatusBadgeModel {
         switch status {
         case .available:
-            return .init(title: "Available", systemImage: "checkmark.circle.fill", foregroundColor: .green, backgroundColor: .green.opacity(0.16))
+            return .init(title: "Available", systemImage: "checkmark.circle.fill", foregroundColor: Color(.statusPositive), backgroundColor: Color(.statusPositive).opacity(0.16))
         case .registered:
-            return .init(title: "Registered", systemImage: "circle.fill", foregroundColor: .yellow, backgroundColor: .yellow.opacity(0.16))
+            return .init(title: "Registered", systemImage: "circle.fill", foregroundColor: Color(.statusWarning), backgroundColor: Color(.statusWarning).opacity(0.16))
         case .unknown, .none:
-            return .init(title: "Unknown", systemImage: "questionmark.circle", foregroundColor: .secondary, backgroundColor: Color(.systemGray5).opacity(0.55))
+            return .init(title: "Unknown", systemImage: "questionmark.circle", foregroundColor: .secondary, backgroundColor: Color(.appSurfaceElevated))
         }
     }
 
     static func tls(sslInfo: SSLCertificateInfo?, error: String?) -> AppStatusBadgeModel {
         if error != nil || sslInfo == nil {
-            return .init(title: "Invalid", systemImage: "xmark.octagon.fill", foregroundColor: .red, backgroundColor: .red.opacity(0.16))
+            return .init(title: "Invalid", systemImage: "xmark.octagon.fill", foregroundColor: Color(.statusCritical), backgroundColor: Color(.statusCritical).opacity(0.16))
         }
         if let sslInfo, sslInfo.daysUntilExpiry <= 14 {
-            return .init(title: "Expiring", systemImage: "exclamationmark.triangle.fill", foregroundColor: .yellow, backgroundColor: .yellow.opacity(0.16))
+            return .init(title: "Expiring", systemImage: "exclamationmark.triangle.fill", foregroundColor: Color(.statusWarning), backgroundColor: Color(.statusWarning).opacity(0.16))
         }
-        return .init(title: "Valid", systemImage: "lock.fill", foregroundColor: .green, backgroundColor: .green.opacity(0.16))
+        return .init(title: "Valid", systemImage: "lock.fill", foregroundColor: Color(.statusPositive), backgroundColor: Color(.statusPositive).opacity(0.16))
     }
 
     static func email(_ result: EmailSecurityResult?, error: String?) -> AppStatusBadgeModel {
         guard error == nil, let result else {
-            return .init(title: "Missing", systemImage: "minus.circle", foregroundColor: .secondary, backgroundColor: Color(.systemGray5).opacity(0.55))
+            return .init(title: "Missing", systemImage: "minus.circle", foregroundColor: .secondary, backgroundColor: Color(.appSurfaceElevated))
         }
 
         let foundCount = [result.spf.found, result.dmarc.found, result.dkim.found].filter { $0 }.count
         switch foundCount {
         case 3:
-            return .init(title: "Secure", systemImage: "checkmark.shield.fill", foregroundColor: .green, backgroundColor: .green.opacity(0.16))
+            return .init(title: "Secure", systemImage: "checkmark.shield.fill", foregroundColor: Color(.statusPositive), backgroundColor: Color(.statusPositive).opacity(0.16))
         case 1, 2:
-            return .init(title: "Partial", systemImage: "shield.lefthalf.filled", foregroundColor: .yellow, backgroundColor: .yellow.opacity(0.16))
+            return .init(title: "Partial", systemImage: "shield.lefthalf.filled", foregroundColor: Color(.statusWarning), backgroundColor: Color(.statusWarning).opacity(0.16))
         default:
-            return .init(title: "Missing", systemImage: "minus.circle", foregroundColor: .secondary, backgroundColor: Color(.systemGray5).opacity(0.55))
+            return .init(title: "Missing", systemImage: "minus.circle", foregroundColor: .secondary, backgroundColor: Color(.appSurfaceElevated))
         }
     }
 
     static func change(_ summary: DomainChangeSummary?) -> AppStatusBadgeModel {
         guard let summary else {
-            return .init(title: "Unchanged", systemImage: "circle", foregroundColor: .secondary, backgroundColor: Color(.systemGray5).opacity(0.55))
+            return .init(title: "Unchanged", systemImage: "circle", foregroundColor: .secondary, backgroundColor: Color(.appSurfaceElevated))
         }
         if summary.hasChanges {
-            return .init(title: "Changed", systemImage: "arrow.triangle.2.circlepath", foregroundColor: .cyan, backgroundColor: .cyan.opacity(0.16))
+            return .init(title: "Changed", systemImage: "arrow.triangle.2.circlepath", foregroundColor: Color(.statusInfo), backgroundColor: Color(.statusInfo).opacity(0.16))
         }
-        return .init(title: "Unchanged", systemImage: "checkmark.circle", foregroundColor: .secondary, backgroundColor: Color(.systemGray5).opacity(0.55))
+        return .init(title: "Unchanged", systemImage: "checkmark.circle", foregroundColor: .secondary, backgroundColor: Color(.appSurfaceElevated))
     }
 }
 
@@ -184,9 +184,9 @@ struct AppCopyButton: View {
         } label: {
             Image(systemName: didCopy ? "checkmark" : "doc.on.doc")
                 .font(appDensity.font(.caption))
-                .foregroundStyle(didCopy ? Color.green : .secondary)
+                .foregroundStyle(didCopy ? Color(.statusPositive) : .secondary)
                 .frame(width: 30, height: 30)
-                .background(Color(.systemGray5).opacity(0.35))
+                .background(Color(.appSurfaceElevated))
                 .clipShape(RoundedRectangle(cornerRadius: 8))
         }
         .buttonStyle(.plain)
@@ -264,11 +264,11 @@ struct EmptyStateCardView: View {
 
             Text(suggestion)
                 .font(appDensity.font(.caption))
-                .foregroundStyle(.cyan)
+                .foregroundStyle(Color(.statusInfo))
         }
         .frame(maxWidth: .infinity, alignment: .leading)
         .padding(appDensity.metrics.cardPadding)
-        .background(showsCardBackground ? Color(.systemGray6).opacity(0.45) : Color.clear)
+        .background(showsCardBackground ? Color(.appSurface) : Color.clear)
         .clipShape(RoundedRectangle(cornerRadius: appDensity.metrics.cardCornerRadius))
     }
 }
@@ -307,7 +307,7 @@ struct CollapsibleSectionView<HeaderTrailing: View, Content: View>: View {
                     VStack(alignment: .leading, spacing: 3) {
                         Text(title)
                             .font(appDensity.font(.headline, design: .default, weight: .semibold))
-                            .foregroundStyle(.white)
+                            .foregroundStyle(.primary)
                         if let subtitle {
                             Text(subtitle)
                                 .font(appDensity.font(.caption))
@@ -346,7 +346,7 @@ struct TagChipRowView: View {
                         .font(.caption)
                         .padding(.horizontal, 10)
                         .padding(.vertical, 5)
-                        .background(Color(.systemGray5).opacity(0.6), in: Capsule())
+                        .background(Color(.appSurfaceElevated), in: Capsule())
                 }
             }
         }
@@ -380,8 +380,8 @@ struct TagFilterChipRowView: View {
                 .font(.caption)
                 .padding(.horizontal, 10)
                 .padding(.vertical, 5)
-                .background(isSelected ? Color.cyan.opacity(0.3) : Color(.systemGray5).opacity(0.6), in: Capsule())
-                .foregroundStyle(isSelected ? Color.cyan : Color.primary)
+                .background(isSelected ? Color(.statusInfo).opacity(0.3) : Color(.appSurfaceElevated), in: Capsule())
+                .foregroundStyle(isSelected ? Color(.statusInfo) : Color.primary)
         }
         .buttonStyle(.plain)
     }