fix: include computed totals in JSON output

Added custom encode(to:) method to DetailedSyncResult to explicitly encode
the computed properties (totalCreated, totalUpdated, totalFailed) in JSON output.

Previously, these computed properties were not included in the JSON because
Swift's Codable only encodes stored properties by default. The workflow needs
these values to generate the sync summary.

**Testing:**
- Verified encode() includes all six fields in JSON output
- Workflow can now parse totalCreated, totalUpdated, totalFailed

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: leogdion

Sources/BushelCloudKit/CloudKit/SyncEngine.swift

@@ -103,6 +103,26 @@ public struct SyncEngine: Sendable {
       self.swiftVersions = swiftVersions
     }
 
+    /// Custom encoding to include computed properties
+    public func encode(to encoder: Encoder) throws {
+      var container = encoder.container(keyedBy: CodingKeys.self)
+      try container.encode(restoreImages, forKey: .restoreImages)
+      try container.encode(xcodeVersions, forKey: .xcodeVersions)
+      try container.encode(swiftVersions, forKey: .swiftVersions)
+      try container.encode(totalCreated, forKey: .totalCreated)
+      try container.encode(totalUpdated, forKey: .totalUpdated)
+      try container.encode(totalFailed, forKey: .totalFailed)
+    }
+
+    private enum CodingKeys: String, CodingKey {
+      case restoreImages
+      case xcodeVersions
+      case swiftVersions
+      case totalCreated
+      case totalUpdated
+      case totalFailed
+    }
+
     /// Convert to JSON string
     public func toJSON(pretty: Bool = false) throws -> String {
       let encoder = JSONEncoder()