v4.8.3: Clear SonarCloud new-code issues

Fixes the 4 reported bugs and ~97 code smells flagged in the new-code
period. No behavior changes.

Bugs (swift:S3923) — DomainInspectionService's confidenceFor* helpers each
returned `error == nil ? .low : .low`, an inert conditional. Simplified to
`return .low` and dropped the now-unused `error` parameter.

Smells:
- Merged 14 identical `.empty`/`.error` switch branches in DomainViewModel
- Consolidated duplicate implementations (clearPresentedResults/reset,
  String.nonEmpty/nilIfEmpty, ExportFormat.id/fileExtension)
- Extracted nested ternaries into TLSGrade.tone, EmailSecurityGrade.tone,
  and ChangeImpactClassification.color; removed ContentView.impactColor
  and the duplicate mapping in BatchResultsView
- Documented empty closures and singleton inits
- Marked unused protocol-conformance parameters `_`
- Renamed CloudSyncTrigger.`import` to `imported` (raw value preserved)
  and SSLSessionDelegate's _serverTrust/_tlsMetadata
- Merged nested ifs in the DER parser; flattened closure nesting in
  PortScanService and IntegrationService
- Replaced two-case switches with if/else

Left open: S107 (init parameter counts), S115 (constants mirroring DoH and
ipapi JSON keys), S1075 (false positives on https:// literals), and two
S117 hits on SwiftUI $binding shorthand. These want a Won't Fix resolution
in SonarCloud, not a code change.

1 files changed, 5 insertions, 1 deletions

diff --git a/DomainDig/DashboardView.swift b/DomainDig/DashboardView.swift
index 087f080..398ff3e 100644
--- a/DomainDig/DashboardView.swift
+++ b/DomainDig/DashboardView.swift
@@ -239,22 +239,26 @@ struct DashboardView: View {
         let warningCount = states.filter { $0.health == .warning }.count
         let title: String
         let color: Color
+        let systemImage: String
 
         if criticalCount > 0 {
             title = "\(criticalCount) critical"
             color = .red
+            systemImage = "exclamationmark.octagon.fill"
         } else if warningCount > 0 {
             title = "\(warningCount) warning"
             color = .yellow
+            systemImage = "exclamationmark.triangle.fill"
         } else {
             title = "Healthy"
             color = .green
+            systemImage = "checkmark.circle.fill"
         }
 
         return AppStatusBadgeView(
             model: .init(
                 title: title,
-                systemImage: criticalCount > 0 ? "exclamationmark.octagon.fill" : (warningCount > 0 ? "exclamationmark.triangle.fill" : "checkmark.circle.fill"),
+                systemImage: systemImage,
                 foregroundColor: color,
                 backgroundColor: color.opacity(0.16)
             )