refactor(launcher): reorganize into responsibility folders

Co-authored-by: Cursor <cursoragent@cursor.com>

LanMountainDesktop.Launcher/AirApp/AirAppInstanceKey.cs

@@ -0,0 +1,24 @@
+namespace LanMountainDesktop.Launcher.AirApp;
+
+internal static class AirAppInstanceKey
+{
+    public static string Build(string appId, string? sourceComponentId, string? sourcePlacementId)
+    {
+        var normalizedAppId = Normalize(appId, "unknown");
+        if (string.Equals(normalizedAppId, "world-clock", StringComparison.OrdinalIgnoreCase))
+        {
+            return $"{normalizedAppId}:clock-suite:global";
+        }
+
+        var normalizedComponentId = Normalize(sourceComponentId, "none");
+        var normalizedPlacementId = Normalize(sourcePlacementId, "none");
+        return $"{normalizedAppId}:{normalizedComponentId}:{normalizedPlacementId}";
+    }
+
+    private static string Normalize(string? value, string fallback)
+    {
+        return string.IsNullOrWhiteSpace(value)
+            ? fallback
+            : value.Trim();
+    }
+}