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, 2 insertions, 2 deletions

diff --git a/DomainDig/CloudSharingSheet.swift b/DomainDig/CloudSharingSheet.swift
index 3d524ef..8318e2a 100644
--- a/DomainDig/CloudSharingSheet.swift
+++ b/DomainDig/CloudSharingSheet.swift
@@ -13,7 +13,7 @@ struct CloudSharingSheet: UIViewControllerRepresentable {
         Coordinator(dismiss: dismiss, title: title)
     }
 
-    func makeUIViewController(context: Context) -> UIViewController {
+    func makeUIViewController(context _: Context) -> UIViewController {
         UIViewController()
     }
 
@@ -77,7 +77,7 @@ struct CloudSharingSheet: UIViewControllerRepresentable {
             }
         }
 
-        func presentationControllerDidDismiss(_ presentationController: UIPresentationController) {
+        func presentationControllerDidDismiss(_: UIPresentationController) {
             dismissAction()
         }
     }