Add startup visual modes and attempt registry

Implement startup visual behavior, de-duplicate startup attempts, and improve failure UX.

Key changes:
- Add spec and docs for startup visuals and timing contract (.trae/specs and docs/LAUNCHER_STARTUP_VISUALS.md).
- Introduce StartupVisualPreferences contract and resolver; create SplashWindow via resolved mode.
- Add StartupAttemptRecord model and a file-backed StartupAttemptRegistry to persist and coordinate in-progress startup attempts (attach/adopt, soft/hard timeouts, IPC/connect state, lifecycle updates).
- Update LauncherFlowCoordinator to: adopt/attach to existing attempts, track IPC connection and soft/hard timeouts (30s/120s), show delayed UI state, attempt foreground recovery via public IPC, compose detailed launch result metadata, and mark registry states (soft timeout, detached waiting, succeeded, failed).
- Add TryActivateExistingInstanceAsync to attempt activating an existing desktop via IPC.
- Change failure flow: ShowFailureWindowAsync now returns user choice; ErrorWindow updated to present Activate/Wait/Open Logs/Exit semantics and new layouts/styles; improved button wiring and debug/dev mode handling.
- Add UI and resource tweaks (ErrorWindow and SplashWindow changes), project asset link for nightly logo, and unit tests for StartupVisualPreferences.

These changes prevent duplicate desktop processes during slow startups, provide clearer UX for delayed startups, and persist startup attempt state across Launcher invocations for safer recovery/attach behavior.

LanMountainDesktop.Shared.Contracts/Launcher/LoadingState.cs

@@ -1,231 +1,85 @@
 namespace LanMountainDesktop.Shared.Contracts.Launcher;
 
-/// <summary>
-/// 加载项类型
-/// </summary>
 public enum LoadingItemType
 {
-    /// <summary>
-    /// 系统初始化
-    /// </summary>
     System,
-    
-    /// <summary>
-    /// 设置加载
-    /// </summary>
     Settings,
-    
-    /// <summary>
-    /// 插件
-    /// </summary>
     Plugin,
-    
-    /// <summary>
-    /// 组件
-    /// </summary>
     Component,
-    
-    /// <summary>
-    /// 资源
-    /// </summary>
     Resource,
-    
-    /// <summary>
-    /// 数据
-    /// </summary>
     Data,
-    
-    /// <summary>
-    /// 网络请求
-    /// </summary>
     Network,
-    
-    /// <summary>
-    /// 其他
-    /// </summary>
     Other
 }
 
-/// <summary>
-/// 加载状态
-/// </summary>
 public enum LoadingState
 {
-    /// <summary>
-    /// 等待中
-    /// </summary>
     Pending,
-    
-    /// <summary>
-    /// 进行中
-    /// </summary>
     InProgress,
-    
-    /// <summary>
-    /// 已完成
-    /// </summary>
     Completed,
-    
-    /// <summary>
-    /// 失败
-    /// </summary>
+    Delayed,
     Failed,
-    
-    /// <summary>
-    /// 已取消
-    /// </summary>
     Cancelled,
-    
-    /// <summary>
-    /// 超时
-    /// </summary>
     Timeout
 }
 
-/// <summary>
-/// 加载项信息
-/// </summary>
 public record LoadingItem
 {
-    /// <summary>
-    /// 加载项唯一标识
-    /// </summary>
     public required string Id { get; init; }
-    
-    /// <summary>
-    /// 加载项类型
-    /// </summary>
+
     public LoadingItemType Type { get; init; }
-    
-    /// <summary>
-    /// 加载项名称
-    /// </summary>
+
     public required string Name { get; init; }
-    
-    /// <summary>
-    /// 加载项描述
-    /// </summary>
+
     public string? Description { get; init; }
-    
-    /// <summary>
-    /// 当前状态
-    /// </summary>
+
     public LoadingState State { get; init; }
-    
-    /// <summary>
-    /// 进度百分比 (0-100)
-    /// </summary>
+
     public int ProgressPercent { get; init; }
-    
-    /// <summary>
-    /// 状态消息
-    /// </summary>
+
     public string? Message { get; init; }
-    
-    /// <summary>
-    /// 错误信息（当 State 为 Failed 时）
-    /// </summary>
+
     public string? ErrorMessage { get; init; }
-    
-    /// <summary>
-    /// 开始时间
-    /// </summary>
+
     public DateTimeOffset? StartTime { get; init; }
-    
-    /// <summary>
-    /// 结束时间
-    /// </summary>
+
     public DateTimeOffset? EndTime { get; init; }
-    
-    /// <summary>
-    /// 预计剩余时间（秒）
-    /// </summary>
+
     public int? EstimatedRemainingSeconds { get; init; }
-    
-    /// <summary>
-    /// 子加载项
-    /// </summary>
+
     public List<LoadingItem>? Children { get; init; }
-    
-    /// <summary>
-    /// 额外数据
-    /// </summary>
+
     public Dictionary<string, string>? Metadata { get; init; }
-    
-    /// <summary>
-    /// 时间戳
-    /// </summary>
+
     public DateTimeOffset Timestamp { get; init; } = DateTimeOffset.UtcNow;
 }
 
-/// <summary>
-/// 加载状态更新消息
-/// </summary>
 public record LoadingStateMessage
 {
-    /// <summary>
-    /// 当前启动阶段
-    /// </summary>
     public StartupStage Stage { get; init; }
-    
-    /// <summary>
-    /// 整体进度百分比 (0-100)
-    /// </summary>
+
     public int OverallProgressPercent { get; init; }
-    
-    /// <summary>
-    /// 当前活动的加载项
-    /// </summary>
+
     public List<LoadingItem> ActiveItems { get; init; } = new();
-    
-    /// <summary>
-    /// 已完成的加载项数量
-    /// </summary>
+
     public int CompletedCount { get; init; }
-    
-    /// <summary>
-    /// 总加载项数量
-    /// </summary>
+
     public int TotalCount { get; init; }
-    
-    /// <summary>
-    /// 状态消息
-    /// </summary>
+
     public string? Message { get; init; }
-    
-    /// <summary>
-    /// 是否有错误
-    /// </summary>
+
     public bool HasErrors { get; init; }
-    
-    /// <summary>
-    /// 错误消息列表
-    /// </summary>
+
     public List<string>? ErrorMessages { get; init; }
-    
-    /// <summary>
-    /// 时间戳
-    /// </summary>
+
     public DateTimeOffset Timestamp { get; init; } = DateTimeOffset.UtcNow;
 }
 
-/// <summary>
-/// 详细的加载进度消息（用于实时更新）
-/// </summary>
 public record DetailedProgressMessage : StartupProgressMessage
 {
-    /// <summary>
-    /// 当前加载项
-    /// </summary>
     public LoadingItem? CurrentItem { get; init; }
-    
-    /// <summary>
-    /// 所有加载项
-    /// </summary>
+
     public List<LoadingItem>? AllItems { get; init; }
-    
-    /// <summary>
-    /// 是否为主要更新
-    /// </summary>
+
     public bool IsMajorUpdate { get; init; }
 }