fix: add reserved keys filter and TOTP reverse mapping in KDBXMapper

MyPassCore/Sources/MyPassCore/KDBX/KDBXMapper.swift

@@ -28,13 +28,15 @@ enum KDBXMapper {
 
     static func entry(from e: KPKEntry) -> Entry {
         // e.customAttributes: only non-default attributes
-        let customFields: [CustomField] = e.customAttributes.map { attr in
-            CustomField(
-                id: UUID(),
-                key: attr.key,
-                value: ProtectedString(attr.value, isProtected: attr.protect)
-            )
-        }
+        let customFields: [CustomField] = e.customAttributes
+            .filter { !reservedKeys.contains($0.key ?? "") }
+            .map { attr in
+                CustomField(
+                    id: UUID(),
+                    key: attr.key,
+                    value: ProtectedString(attr.value, isProtected: attr.protect)
+                )
+            }
 
         // Parse TOTP from the otp URI attribute (KeePassOTP format)
         let totpURI = e.customAttributes.first { $0.key == "otp" }?.value
@@ -105,6 +107,11 @@ enum KDBXMapper {
             )
             kpk.addCustomAttribute(attr)
         }
+        if let totp = e.totp {
+            let uri = totpURI(from: totp)
+            let attr = KPKAttribute(key: "otp", value: uri, isProtected: false)
+            kpk.addCustomAttribute(attr)
+        }
         for att in e.attachments {
             let bin = KPKBinary(name: att.name, data: att.data)
             kpk.addBinary(bin)
@@ -118,4 +125,20 @@ enum KDBXMapper {
         guard let u = nsUUID else { return UUID() }
         return UUID(uuidString: u.uuidString) ?? UUID()
     }
+
+    private static func totpURI(from config: TOTPConfig) -> String {
+        var components = URLComponents()
+        components.scheme = "otpauth"
+        components.host = "totp"
+        components.path = "/MyPass"
+        components.queryItems = [
+            URLQueryItem(name: "secret", value: config.secret),
+            URLQueryItem(name: "period", value: String(config.period)),
+            URLQueryItem(name: "digits", value: String(config.digits)),
+            URLQueryItem(name: "algorithm", value: config.algorithm.rawValue),
+        ]
+        return components.url?.absoluteString ?? ""
+    }
+
+    private static let reservedKeys: Set<String> = ["Title", "UserName", "Password", "URL", "Notes"]
 }