Add connection history per peer with country and network lookup

- The stats sampler records sessions per peer: start, end, address and
  traffic. A session ends when the peer goes quiet or is disabled; a new
  one starts when the device changes networks. Stored in stats.json and
  kept as long as the daily traffic history (max 1000 per peer).
- Country and network operator come from the free DB-IP Lite databases
  (CC BY 4.0), downloaded monthly and looked up locally, so peer
  addresses never leave the server. Settings → Data retention can switch
  this off, which deletes the databases.
- API: GET /peers/{id}/sessions; peer stats include the current location;
  settings include the database status.
- Web UI and iOS app: connection history card, location line, country
  code in the peer list (web), switch in data retention.

Claude-Session: https://claude.ai/code/session_01RAnLbyQZ5ZTA7KqwXP98nw

ios/GHOSTWIRE/Format.swift

@@ -33,6 +33,16 @@ func fmtDate(_ date: Date?) -> String {
     return date.formatted(date: .abbreviated, time: .omitted)
 }
 
+/// "35 min", "2 h 5 min", "3 days".
+func fmtDuration(_ seconds: Int64) -> String {
+    if seconds < 60 { return "under 1 min" }
+    let m = Int((Double(seconds) / 60).rounded())
+    if m < 60 { return "\(m) min" }
+    let h = m / 60
+    if h < 48 { return "\(h) h \(m % 60) min" }
+    return "\(Int((Double(h) / 24).rounded())) days"
+}
+
 /// Label of a chart point: "3 h ago" for hours, "Sat 3 Oct" for days.
 func pointLabel(_ p: StatPoint, range: String) -> String {
     if range == "24h" {

ios/GHOSTWIRE/Models.swift

@@ -61,6 +61,38 @@ nonisolated struct PeerStats: Decodable, Hashable {
     let lastHandshake: Date?
     let endpoint: String
     let down24h, up24h, down30d, up30d, downTotal, upTotal: Int64
+    let location: GeoInfo?
+}
+
+/// Country and network of an address, from the server's DB-IP lookup.
+nonisolated struct GeoInfo: Decodable, Hashable {
+    let country: String?
+    let countryName: String?
+    let asn: Int?
+    let network: String?
+
+    /// "Germany · Deutsche Telekom AG" or "Local network".
+    var label: String {
+        [countryName ?? country, network].compactMap { $0 }.filter { !$0.isEmpty }.joined(separator: " · ")
+    }
+}
+
+/// One row of a peer's connection history.
+nonisolated struct ConnSession: Decodable, Identifiable, Hashable {
+    let start: Date
+    let end: Date
+    let open: Bool
+    let seconds: Int64
+    let endpoint: String
+    let ip: String
+    let geo: GeoInfo?
+    let down: Int64
+    let up: Int64
+    var id: String { "\(start.timeIntervalSince1970)-\(ip)" }
+}
+
+nonisolated struct SessionsResponse: Decodable {
+    let sessions: [ConnSession]
 }
 
 nonisolated struct Peer: Decodable, Identifiable, Hashable {
@@ -166,6 +198,12 @@ nonisolated struct LogSettings: Codable, Equatable {
 nonisolated struct StatsSettings: Codable, Equatable {
     var hourlyHours: Int
     var dailyDays: Int
+    var geoip: Bool?
+}
+
+nonisolated struct GeoStatus: Decodable {
+    let enabled: Bool
+    let updated: Date?
 }
 
 nonisolated struct AppSettings: Decodable {
@@ -175,6 +213,7 @@ nonisolated struct AppSettings: Decodable {
     var adminUsername: String
     var fingerprint: String
     var logPath: String
+    var geo: GeoStatus?
 }
 
 nonisolated struct SettingsResult: Decodable {

ios/GHOSTWIRE/PeerDetailView.swift

@@ -15,8 +15,11 @@ struct PeerDetailView: View {
     @State private var askKey = false
     @State private var deviceKey = ""
     @State private var editing = false
+    @State private var sessions: [ConnSession] = []
+    @State private var allSessions = false
 
     var body: some View {
+        ScrollViewReader { proxy in
         ScrollView {
             VStack(spacing: 16) {
                 if let error { Notice(text: error, isError: true) }
@@ -24,6 +27,7 @@ struct PeerDetailView: View {
                     header(p)
                     traffic
                     connection(p)
+                    history.id("history")
                     clientConfig(p)
                     settings(p)
                 } else if error == nil {
@@ -33,6 +37,13 @@ struct PeerDetailView: View {
             .padding(16)
         }
         .background(Color.gwGround)
+        #if DEBUG
+        // Development: `-scrollToHistory YES` for screenshots of the history.
+        .task(id: sessions.count) {
+            if UserDefaults.standard.bool(forKey: "scrollToHistory"), !sessions.isEmpty { proxy.scrollTo("history", anchor: .top) }
+        }
+        #endif
+        }
         .navigationTitle(peer?.name ?? "Peer")
         .navigationBarTitleDisplayMode(.inline)
         .toolbar {
@@ -107,6 +118,7 @@ struct PeerDetailView: View {
             SectionTitle(text: "Connection")
             KV(key: "Tunnel address", value: p.ipv4 + "/32" + (p.ipv6.map { "\n" + $0 + "/128" } ?? ""), mono: true)
             KV(key: "Endpoint", value: p.stats.endpoint.isEmpty ? "–" : p.stats.endpoint, mono: true)
+            KV(key: "Location", value: p.stats.location?.label.isEmpty == false ? p.stats.location!.label : "–")
             KV(key: "Latest handshake", value: ago(p.stats.lastHandshake))
             KV(key: "Public key", value: p.publicKey, mono: true)
             KV(key: "Preshared key", value: p.hasPresharedKey ? "Set" : "None")
@@ -115,6 +127,66 @@ struct PeerDetailView: View {
         .card()
     }
 
+    private var history: some View {
+        VStack(alignment: .leading, spacing: 0) {
+            SectionTitle(text: "Connection history")
+            Text("Newest first. A new row starts when the device changes networks.")
+                .font(.caption)
+                .foregroundStyle(Color.gwText2)
+                .padding(.bottom, 8)
+            if sessions.isEmpty {
+                Text("No connections recorded yet.").font(.footnote).foregroundStyle(Color.gwText2).padding(.vertical, 6)
+            }
+            let shown = allSessions ? sessions : Array(sessions.prefix(8))
+            ForEach(shown) { se in
+                HStack(alignment: .top, spacing: 12) {
+                    VStack(alignment: .leading, spacing: 4) {
+                        HStack(spacing: 6) {
+                            Text(se.start.formatted(.dateTime.day().month(.abbreviated).hour().minute()))
+                                .font(.subheadline.weight(.medium))
+                            if se.open {
+                                HStack(spacing: 4) {
+                                    Circle().fill(Color.gwGood).frame(width: 6, height: 6)
+                                    Text("online")
+                                }
+                                .font(.caption.weight(.medium))
+                                .padding(.horizontal, 6).padding(.vertical, 2)
+                                .background(Color.gwBadge, in: Capsule())
+                            }
+                        }
+                        Text(se.geo?.label.isEmpty == false ? se.geo!.label : "Unknown location")
+                            .font(.footnote)
+                            .foregroundStyle(se.geo == nil ? Color.gwText2 : Color.gwText)
+                        Text(se.ip + " · " + fmtDuration(se.seconds))
+                            .font(.mono(.caption))
+                            .foregroundStyle(Color.gwText2)
+                    }
+                    Spacer(minLength: 8)
+                    VStack(alignment: .trailing, spacing: 4) {
+                        Text("↓ " + fmtBytes(se.down)).font(.footnote.monospacedDigit())
+                        Text("↑ " + fmtBytes(se.up)).font(.footnote.monospacedDigit()).foregroundStyle(Color.gwText2)
+                    }
+                }
+                .padding(.vertical, 8)
+                .accessibilityElement(children: .combine)
+                if se.id != shown.last?.id { Divider() }
+            }
+            if sessions.count > 8 {
+                Button(allSessions ? "Show fewer" : "Show all \(sessions.count)") { allSessions.toggle() }
+                    .font(.footnote.weight(.medium))
+                    .padding(.top, 8)
+            }
+            HStack(spacing: 4) {
+                Text("Country and network:")
+                Link("IP Geolocation by DB-IP", destination: URL(string: "https://db-ip.com")!).underline()
+            }
+            .font(.caption2)
+            .foregroundStyle(Color.gwText2)
+            .padding(.top, 10)
+        }
+        .card()
+    }
+
     private func clientConfig(_ p: Peer) -> some View {
         VStack(alignment: .leading, spacing: 12) {
             SectionTitle(text: "Client configuration")
@@ -154,6 +226,7 @@ struct PeerDetailView: View {
             (peer, server) = try await (p, s)
             error = nil
             await loadStats()
+            if let r: SessionsResponse = try? await api.get("/peers/\(peerID)/sessions?limit=100") { sessions = r.sessions }
         } catch {
             self.error = session.message(for: error)
         }

ios/GHOSTWIRE/SettingsView.swift

@@ -139,6 +139,12 @@ struct SettingsView: View {
             Picker("Daily traffic history", selection: s.dailyDays) {
                 ForEach(options(Self.daily, current: stats!.dailyDays, unit: "days"), id: \.0) { Text($0.1).tag($0.0) }
             }
+            Toggle(isOn: Binding(get: { stats!.geoip ?? true }, set: { stats!.geoip = $0 })) {
+                VStack(alignment: .leading, spacing: 2) {
+                    Text("Show country and network")
+                    Text(geoStatusText).font(.caption).foregroundStyle(Color.gwText2)
+                }
+            }
             Button("Save retention") {
                 guard let old = settings, let log, let stats else { return }
                 if log.maxFiles < old.log.maxFiles || stats.hourlyHours < old.stats.hourlyHours || stats.dailyDays < old.stats.dailyDays {
@@ -151,7 +157,7 @@ struct SettingsView: View {
         } header: {
             Text("Data retention")
         } footer: {
-            Text("The log uses up to \(log!.maxSizeMB * (log!.maxFiles + 1)) MB on disk. All-time traffic totals are always kept. Applies immediately.")
+            Text("The log uses up to \(log!.maxSizeMB * (log!.maxFiles + 1)) MB on disk. Connection history is kept as long as the daily traffic history; all-time totals are always kept. Country and network come from the free DB-IP Lite databases, downloaded monthly and looked up on the server only. Applies immediately.")
         }
     }
 
@@ -171,6 +177,11 @@ struct SettingsView: View {
         }
     }
 
+    private var geoStatusText: String {
+        guard let updated = settings?.geo?.updated else { return "Database not downloaded yet" }
+        return "Database from \(fmtDate(updated))"
+    }
+
     private func options(_ presets: [(Int, String)], current: Int, unit: String) -> [(Int, String)] {
         presets.contains { $0.0 == current } ? presets : (presets + [(current, "\(current) \(unit)")]).sorted { $0.0 < $1.0 }
     }