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, 14 insertions, 14 deletions

diff --git a/DomainDig/MonitoringView.swift b/DomainDig/MonitoringView.swift
index fc0b8ab..decad35 100644
--- a/DomainDig/MonitoringView.swift
+++ b/DomainDig/MonitoringView.swift
@@ -41,7 +41,7 @@ struct MonitoringView: View {
                 }
                 .padding(.vertical, 4)
             }
-            .listRowBackground(Color(.systemGray6).opacity(0.5))
+            .listRowBackground(Color(.appSurface))
 
             if viewModel.monitoringLogs.isEmpty {
                 Section {
@@ -53,7 +53,7 @@ struct MonitoringView: View {
                         showsCardBackground: false
                     )
                 }
-                .listRowBackground(Color(.systemGray6).opacity(0.5))
+                .listRowBackground(Color(.appSurface))
             } else {
                 Section("Recent Runs") {
                     ForEach(viewModel.monitoringLogs) { log in
@@ -78,10 +78,10 @@ struct MonitoringView: View {
                                 HStack(spacing: 8) {
                                     metricBadge(title: "\(log.domainsChecked) checked")
                                     if log.changesFound > 0 {
-                                        metricBadge(title: "\(log.changesFound) changed", tint: .orange)
+                                        metricBadge(title: "\(log.changesFound) changed", tint: Color(.statusWarning))
                                     }
                                     if log.alertsTriggered > 0 {
-                                        metricBadge(title: "\(log.alertsTriggered) alerts", tint: .red)
+                                        metricBadge(title: "\(log.alertsTriggered) alerts", tint: Color(.statusCritical))
                                     }
                                 }
                             }
@@ -89,11 +89,11 @@ struct MonitoringView: View {
                         }
                     }
                 }
-                .listRowBackground(Color(.systemGray6).opacity(0.5))
+                .listRowBackground(Color(.appSurface))
             }
         }
         .scrollContentBackground(.hidden)
-        .background(Color.black)
+        .background(Color(.appBackground))
         .navigationTitle("Monitoring")
         .preferredColorScheme(.dark)
         .onAppear {
@@ -101,7 +101,7 @@ struct MonitoringView: View {
         }
     }
 
-    private func metricBadge(title: String, tint: Color = .cyan) -> some View {
+    private func metricBadge(title: String, tint: Color = Color(.statusInfo)) -> some View {
         Text(title)
             .font(appDensity.font(.caption2))
             .foregroundStyle(tint)
@@ -133,7 +133,7 @@ struct MonitoringLogDetailView: View {
                 LabeledContent("Alerts", value: "\(log.alertsTriggered)")
                 LabeledContent("Timestamp", value: log.timestamp.formatted(date: .abbreviated, time: .shortened))
             }
-            .listRowBackground(Color(.systemGray6).opacity(0.5))
+            .listRowBackground(Color(.appSurface))
 
             Section("Domains") {
                 ForEach(log.checkedDomains) { result in
@@ -167,7 +167,7 @@ struct MonitoringLogDetailView: View {
                         if let errorMessage = result.errorMessage {
                             Text(errorMessage)
                                 .font(appDensity.font(.caption2))
-                                .foregroundStyle(.yellow)
+                                .foregroundStyle(Color(.statusWarning))
                         }
 
                         if let historyEntryID = result.historyEntryID,
@@ -181,7 +181,7 @@ struct MonitoringLogDetailView: View {
                     .padding(.vertical, 4)
                 }
             }
-            .listRowBackground(Color(.systemGray6).opacity(0.5))
+            .listRowBackground(Color(.appSurface))
 
             if !log.errors.isEmpty {
                 Section("Errors") {
@@ -191,11 +191,11 @@ struct MonitoringLogDetailView: View {
                             .foregroundStyle(.secondary)
                     }
                 }
-                .listRowBackground(Color(.systemGray6).opacity(0.5))
+                .listRowBackground(Color(.appSurface))
             }
         }
         .scrollContentBackground(.hidden)
-        .background(Color.black)
+        .background(Color(.appBackground))
         .navigationTitle("Run Details")
         .preferredColorScheme(.dark)
     }
@@ -205,9 +205,9 @@ struct MonitoringLogDetailView: View {
         case .info:
             return .secondary
         case .warning:
-            return .yellow
+            return Color(.statusWarning)
         case .critical:
-            return .red
+            return Color(.statusCritical)
         }
     }
 }