[O] Better understanding of the data type of different games

src/main/java/icu/samnyan/aqua/net/UserRegistrar.kt

@@ -30,11 +30,11 @@ class UserRegistrar(
     val emailProps: EmailProperties
 ) {
     companion object {
-        // Random long with length 9 (10^10 possibilities)
-        // This is because DIVA is using int for card ID, which is at max 10 digits (2147483647)
-        // TODO: Figure out if DIVA can handle int64
+        // Random long with length 9-10
+        // We chose 1e9 as the start because normal cards took 0...1e9-1
+        // This is because games can only take uint32 for card ID, which is at max 10 digits (4294967295)
         const val cardExtIdStart = 1e9.toLong()
-        const val cardExtIdEnd = 1e10.toLong() - 1
+        const val cardExtIdEnd = 4294967295
     }
 
     /**

src/main/java/icu/samnyan/aqua/sega/general/model/Card.kt

@@ -18,7 +18,8 @@ class Card(
     @JsonIgnore
     val id: Long = 0,
 
-    // A external id
+    // An external id (THIS IS UINT32!!!!)
+    // IDK why samnyan used Long, Games cannot parse the full int64 value and will cast it to uint32
     @Column(name = "ext_id", unique = true, nullable = false)
     @JsonIgnore // Sensitive information
     var extId: Long = 0,
@@ -48,5 +49,6 @@ class Card(
         private val serialVersionUID = 1L
     }
 
+    @Suppress("unused") // Used by serialization
     val isLinked get() = aquaUser != null
 }