add support for multiple BML accounts, and BML credit cards

app/src/main/java/sh/sar/basedbank/BasedBankApp.kt

@@ -19,11 +19,19 @@ class BasedBankApp : Application() {
     var fullName: String = ""
     var mibSession: MibSession? = null
     var mibProfiles: List<MibProfile> = emptyList()
-    var bmlSession: BmlSession? = null
+    /** Active BML sessions keyed by loginId (= BML username). */
+    val bmlSessions: MutableMap<String, BmlSession> = mutableMapOf()
     var bmlAccounts: List<MibAccount> = emptyList()
     var fahipaySession: FahipaySession? = null
     var fahipayAccounts: List<MibAccount> = emptyList()
 
+    /** Returns the BML session for the given account (matched via loginTag). */
+    fun bmlSessionFor(account: MibAccount): BmlSession? =
+        bmlSessions[account.loginTag.removePrefix("bml_")]
+
+    /** Returns any available BML session (for non-account-specific operations). */
+    fun anyBmlSession(): BmlSession? = bmlSessions.values.firstOrNull()
+
     /** Serialises all MIB profile-switch + request sequences to prevent session corruption. */
     val mibMutex = Mutex()