feat: add network diagnostics extension

ARCHITECTURE.md

@@ -185,3 +185,5 @@ endpoint, provider credentials, and the signed update channel. Changes that
 cross one of these boundaries should document the data flow, minimize retained
 data, fail closed, and include focused tests for authorization, parsing, and
 error handling.
+
+Network Diagnostics belongs to the System suite. The window, menu panel and CLI submit typed operations to the agent; the agent serializes scans, stores a bounded timeline in SQLite and schedules opt-in checks. Shared notification delivery keeps alerts working with the window closed. The agent does not request Wi-Fi or notification permissions.

Packages/Edith/Sources/Edith/Core/Navigation/NavigationCatalog.swift

@@ -148,6 +148,9 @@ enum NavigationCatalog {
         SidebarPage(
             id: "system", title: "System", symbolName: "switch.2", band: .suite(.system),
             isSuiteLanding: true, expansionKey: SuiteExpansion.key(for: .system)),
+        SidebarPage(
+            id: "network", title: "Network", symbolName: "network",
+            band: .suite(.system), abilityIDs: ["networkDiagnostics"], parentID: "system"),
         SidebarPage(
             id: "runningApps", title: "Running apps", symbolName: "cpu",
             band: .suite(.system), abilityIDs: ["system"], parentID: "system"),
@@ -267,7 +270,7 @@ enum MainDestination: String, CaseIterable, Identifiable {
     case home, machines
     case agents, dashboard, herdr, quinjet, companion, plugins
     case appMaintenance
-    case system, runningApps
+    case system, runningApps, network
     case desk
     case media, music, calendar
     case data, database, attention, seoAudit

Packages/Edith/Sources/Edith/Core/Navigation/PageContent.swift

@@ -23,6 +23,7 @@ struct PageContent: View {
         case .appMaintenance: AppMaintenanceView()
         case .system: SuiteLandingPage(suite: SuiteRegistry.suite(.system))
         case .runningApps: SystemPage()
+        case .network: NetworkDiagnosticsPage()
         case .desk: SuiteLandingPage(suite: SuiteRegistry.suite(.desk))
         case .media: SuiteLandingPage(suite: SuiteRegistry.suite(.media))
         case .music: MusicPage()