release(ios): 发布 0.2.1 并重构图标与界面细节

- 应用图标改用与 Web favicon 同源的扁平标记，金色 SIM 卡体加三格递增信号，29pt 下仍可读
- 标签统一为胶囊形状，提高深色主题下的描边权重，避免标签在暗色下消失
- 消息卡片与详情分区卡片收紧行距，单屏信息密度明显提升
- 详情头部指标精简为 4 行，数据模块改为单条读数
- 批量选择勾选框移出名称区域，工具栏控件统一为等高 34pt
- 分组编辑器改为点选即生效，移除说明文字与常驻禁用按钮

apps/ios/Sources/MultiSimAdmin/Features/Fleet/FleetViewModel.swift

@@ -4,7 +4,6 @@ import SwiftUI
 enum FleetGroupMode: String, CaseIterable, Identifiable {
     case none
     case status
-    case tags
     case groups
 
     var id: String { rawValue }
@@ -13,7 +12,6 @@ enum FleetGroupMode: String, CaseIterable, Identifiable {
         switch self {
         case .none: return "平铺"
         case .status: return "状态"
-        case .tags: return "标签"
         case .groups: return "分组"
         }
     }
@@ -184,12 +182,15 @@ final class FleetViewModel: ObservableObject {
     @Published var rows: [Row] = []
     @Published var searchText = ""
     @Published var statusFilter: ConnectionStatus?
-    @Published var groupMode: FleetGroupMode = {
-        let stored = UserDefaults.standard.string(forKey: "fleet.groupMode")
-        return FleetGroupMode(rawValue: stored ?? "") ?? .groups
-    }() {
+    @Published var groupMode: FleetGroupMode = .groups {
         didSet {
-            UserDefaults.standard.set(groupMode.rawValue, forKey: "fleet.groupMode")
+            preferences.set(groupMode.rawValue, forKey: "fleet.groupMode")
+        }
+    }
+    @Published var selectedTagFilters: Set<String> = [] {
+        didSet {
+            let values = Array(selectedTagFilters).sorted()
+            preferences.set(values, forKey: "fleet.selectedTagFilters")
         }
     }
     @Published var selectedIDs: Set<UUID> = []
@@ -206,19 +207,35 @@ final class FleetViewModel: ObservableObject {
     private let credentials: any CredentialStore
     private let deviceService: (any DeviceSummaryService)?
     private let groupStore: (any InstanceGroupStore)?
+    private let preferences: UserDefaults
 
     init(
         repository: any InstanceRepository,
         probe: ConnectionProbe,
         credentials: any CredentialStore,
         deviceService: (any DeviceSummaryService)? = nil,
-        groupStore: (any InstanceGroupStore)? = nil
+        groupStore: (any InstanceGroupStore)? = nil,
+        preferences: UserDefaults = .standard
     ) {
         self.repository = repository
         self.probe = probe
         self.credentials = credentials
         self.deviceService = deviceService
         self.groupStore = groupStore
+        self.preferences = preferences
+        // 旧版本的「按标签分组」已废弃，标签现在只作为筛选条件存在。
+        let storedMode = preferences.string(forKey: "fleet.groupMode")
+        groupMode = FleetGroupMode(rawValue: storedMode ?? "") ?? .groups
+        selectedTagFilters = Set(preferences.stringArray(forKey: "fleet.selectedTagFilters") ?? [])
+    }
+
+    /// 节点列表变化后，丢弃已经不存在任何实例的标签筛选，避免列表被隐藏条件清空。
+    func pruneTagFilters() {
+        guard selectedTagFilters.isEmpty == false else { return }
+        let live = selectedTagFilters.filter { countForTagFilter($0) > 0 }
+        if live != selectedTagFilters {
+            selectedTagFilters = live
+        }
     }
 
     func refresh() async {
@@ -243,6 +260,7 @@ final class FleetViewModel: ObservableObject {
         } catch {
             errorMessage = "无法刷新节点列表"
         }
+        pruneTagFilters()
         lastRefresh = Date()
         isLoading = false
     }
@@ -400,6 +418,13 @@ final class FleetViewModel: ObservableObject {
             if let statusFilter, row.status != statusFilter {
                 return false
             }
+            if selectedTagFilters.isEmpty == false {
+                let tags = Set(row.instance.tags.map { Self.normalizedTag($0) })
+                let needles = Set(selectedTagFilters.map { Self.normalizedTag($0) })
+                guard needles.isSubset(of: tags) else {
+                    return false
+                }
+            }
             guard !searchText.isEmpty else { return true }
             let haystacks: [String] = [
                 row.instance.name,
@@ -417,6 +442,47 @@ final class FleetViewModel: ObservableObject {
         }
     }
 
+    var allTags: [String] {
+        Array(tagCounts.keys).sorted { $0.localizedCompare($1) == .orderedAscending }
+    }
+
+    var tagCounts: [String: Int] {
+        var counts: [String: Int] = [:]
+        for row in rows {
+            for tag in Set(row.instance.tags.map(Self.normalizedTag)) where tag.isEmpty == false {
+                counts[tag, default: 0] += 1
+            }
+        }
+        return counts
+    }
+
+    func countForTagFilter(_ tag: String) -> Int {
+        tagCounts[Self.normalizedTag(tag)] ?? 0
+    }
+
+    func isTagFilterActive(_ tag: String) -> Bool {
+        selectedTagFilters.contains(Self.normalizedTag(tag))
+    }
+
+    func toggleTagFilter(_ tag: String) {
+        let normalized = Self.normalizedTag(tag)
+        guard normalized.isEmpty == false else { return }
+        if selectedTagFilters.contains(normalized) {
+            selectedTagFilters.remove(normalized)
+        } else {
+            selectedTagFilters.insert(normalized)
+        }
+    }
+
+    func clearTagFilters() {
+        guard selectedTagFilters.isEmpty == false else { return }
+        selectedTagFilters.removeAll()
+    }
+
+    private static func normalizedTag(_ tag: String) -> String {
+        tag.trimmingCharacters(in: .whitespacesAndNewlines).lowercased()
+    }
+
     var groupedRows: [FleetGroup] {
         let rows = visibleRows.sorted {
             $0.instance.name.localizedCompare($1.instance.name) == .orderedAscending
@@ -431,19 +497,6 @@ final class FleetViewModel: ObservableObject {
                 guard !matched.isEmpty else { return nil }
                 return FleetGroup(id: status.rawValue, title: status.label, rows: matched)
             }
-        case .tags:
-            let tags = Array(Set(rows.flatMap(\.instance.tags))).sorted()
-            let grouped = tags.map { tag in
-                FleetGroup(
-                    id: tag,
-                    title: tag,
-                    rows: rows.filter { $0.instance.tags.contains(tag) }
-                )
-            }
-            let untagged = rows.filter { $0.instance.tags.isEmpty }
-            return grouped + (untagged.isEmpty
-                ? []
-                : [FleetGroup(id: "__untagged__", title: "未打标签", rows: untagged)])
         case .groups:
             var groupedRows: [UUID: [Row]] = [:]
             var ungroupedRows: [Row] = []