refactor: extract WelcomeViewModel and split WelcomeWindowView into focused files

Author: datlechin

TablePro/Core/Storage/GroupStorage.swift

@@ -15,21 +15,28 @@ final class GroupStorage {
     private let defaults = UserDefaults.standard
     private let encoder = JSONEncoder()
     private let decoder = JSONDecoder()
+    private var cachedGroups: [ConnectionGroup]?
 
     private init() {}
 
     // MARK: - Group CRUD
 
     /// Load all groups
     func loadGroups() -> [ConnectionGroup] {
+        if let cached = cachedGroups { return cached }
+
         guard let data = defaults.data(forKey: groupsKey) else {
+            cachedGroups = []
             return []
         }
 
         do {
-            return try decoder.decode([ConnectionGroup].self, from: data)
+            let groups = try decoder.decode([ConnectionGroup].self, from: data)
+            cachedGroups = groups
+            return groups
         } catch {
             Self.logger.error("Failed to load groups: \(error)")
+            cachedGroups = []
             return []
         }
     }
@@ -39,6 +46,7 @@ final class GroupStorage {
         do {
             let data = try encoder.encode(groups)
             defaults.set(data, forKey: groupsKey)
+            cachedGroups = nil
             SyncChangeTracker.shared.markDirty(.group, ids: groups.map { $0.id.uuidString })
         } catch {
             Self.logger.error("Failed to save groups: \(error)")

TablePro/Core/Storage/TagStorage.swift

@@ -17,6 +17,7 @@ final class TagStorage {
     private let defaults = UserDefaults.standard
     private let encoder = JSONEncoder()
     private let decoder = JSONDecoder()
+    private var cachedTags: [ConnectionTag]?
 
     private init() {
         // Initialize with presets on first launch
@@ -29,16 +30,23 @@ final class TagStorage {
 
     /// Load all tags (presets + custom)
     func loadTags() -> [ConnectionTag] {
+        if let cached = cachedTags { return cached }
+
         guard let data = defaults.data(forKey: tagsKey) else {
-            return ConnectionTag.presets
+            let tags = ConnectionTag.presets
+            cachedTags = tags
+            return tags
         }
 
         do {
             let tags = try decoder.decode([ConnectionTag].self, from: data)
+            cachedTags = tags
             return tags
         } catch {
             Self.logger.error("Failed to load tags: \(error)")
-            return ConnectionTag.presets
+            let tags = ConnectionTag.presets
+            cachedTags = tags
+            return tags
         }
     }
 
@@ -47,6 +55,7 @@ final class TagStorage {
         do {
             let data = try encoder.encode(tags)
             defaults.set(data, forKey: tagsKey)
+            cachedTags = nil
             SyncChangeTracker.shared.markDirty(.tag, ids: tags.map { $0.id.uuidString })
         } catch {
             Self.logger.error("Failed to save tags: \(error)")