Complete v4.5.0: Run Sweep intent, detail deep link, and portfolio widget

Finishes the v4.5.0 "Home Screen & Shortcuts reach" scope that the tag shipped
partially:

- Add RunSweepIntent (opens the app and runs refreshAllTrackedDomains via the
  in-process router) and expose it in DomainDigShortcuts.
- Extend the domaindig:// scheme with `sweep` and `domain` (detail) actions;
  route .detail to present TrackedDomainDetailView and .sweep to refresh the
  watchlist. Move DomainDigDeepLink into Shared/ so the widget can build links.
- Add a WidgetKit extension (DomainDigWidgetExtension) with small/medium/large
  Portfolio widgets showing health counts, per-domain status, and certificate
  countdowns; tapping a domain deep-links into its detail.
- Share portfolio state via an App Group (group.net.cleberg.DomainDig): the app
  writes a DomainDigWidgetData snapshot on launch/foreground and on watchlist
  changes and reloads timelines; the widget reads the same store.

1 files changed, 82 insertions, 0 deletions

diff --git a/Shared/DomainDigWidgetData.swift b/Shared/DomainDigWidgetData.swift
new file mode 100644
index 0000000..5ceae48
--- /dev/null
+++ b/Shared/DomainDigWidgetData.swift
@@ -0,0 +1,82 @@
+import Foundation
+
+/// App Group + snapshot shared between the app (writer) and the widget (reader).
+///
+/// Deliberately self-contained: it references no app-target types (TrackedDomain,
+/// PortfolioSnapshot, DomainHealth, …) so it compiles unchanged into the widget
+/// extension. The app maps its richer types into these DTOs.
+enum DomainDigWidgetStore {
+    static let appGroupID = "group.net.cleberg.DomainDig"
+    private static let key = "widgetData"
+
+    private static var defaults: UserDefaults? {
+        UserDefaults(suiteName: appGroupID)
+    }
+
+    static func write(_ data: DomainDigWidgetData) {
+        guard let defaults, let encoded = try? JSONEncoder().encode(data) else { return }
+        defaults.set(encoded, forKey: key)
+    }
+
+    static func read() -> DomainDigWidgetData? {
+        guard let defaults,
+              let encoded = defaults.data(forKey: key),
+              let data = try? JSONDecoder().decode(DomainDigWidgetData.self, from: encoded)
+        else { return nil }
+        return data
+    }
+}
+
+struct DomainDigWidgetData: Codable, Sendable {
+    var generatedAt: Date
+    var totalDomains: Int
+    var healthyCount: Int
+    var warningCount: Int
+    var criticalCount: Int
+    var expiringSoonCount: Int
+    var unreachableCount: Int
+    var domains: [DomainDigWidgetDomain]
+
+    static let placeholder = DomainDigWidgetData(
+        generatedAt: .distantPast,
+        totalDomains: 3,
+        healthyCount: 2,
+        warningCount: 1,
+        criticalCount: 0,
+        expiringSoonCount: 1,
+        unreachableCount: 0,
+        domains: [
+            DomainDigWidgetDomain(domain: "example.com", isPinned: true, status: .healthy, certDaysRemaining: 240, lastChange: nil),
+            DomainDigWidgetDomain(domain: "cleberg.net", isPinned: false, status: .warning, certDaysRemaining: 21, lastChange: nil),
+            DomainDigWidgetDomain(domain: "example.org", isPinned: false, status: .healthy, certDaysRemaining: 88, lastChange: nil)
+        ]
+    )
+
+    /// Empty state used before the app has written any data.
+    static let empty = DomainDigWidgetData(
+        generatedAt: .distantPast,
+        totalDomains: 0,
+        healthyCount: 0,
+        warningCount: 0,
+        criticalCount: 0,
+        expiringSoonCount: 0,
+        unreachableCount: 0,
+        domains: []
+    )
+}
+
+struct DomainDigWidgetDomain: Codable, Sendable, Identifiable {
+    var domain: String
+    var isPinned: Bool
+    var status: DomainDigWidgetStatus
+    var certDaysRemaining: Int?
+    var lastChange: Date?
+
+    var id: String { domain }
+}
+
+enum DomainDigWidgetStatus: String, Codable, Sendable {
+    case healthy
+    case warning
+    case critical
+}