added support for QR payments from BML gateway

app/src/main/java/sh/sar/basedbank/api/bml/BmlQrPayClient.kt

@@ -35,6 +35,39 @@ class BmlQrPayClient {
         }
     }
 
+    /**
+     * Pre-initiate step required for gateway QR (pay.bml.com.mv).
+     * POST without channel — expects code 99 (OTP channel selection required).
+     */
+    fun preInitiatePayment(
+        session: BmlSession,
+        debitAccount: String,
+        requestId: String,
+        amount: Double,
+        currency: String
+    ): Boolean {
+        val jo = JSONObject().apply {
+            put("action", "approve")
+            put("debitAccount", debitAccount)
+            put("requestId", requestId)
+            put("amount", amount)
+            put("currency", currency)
+        }
+        val request = Request.Builder()
+            .url("$BML_BASE_URL/api/mobile/walletpayments/pay")
+            .post(jo.toString().toRequestBody("application/json".toMediaType()))
+            .header("Authorization", "Bearer ${session.accessToken}")
+            .header("User-Agent", BML_USER_AGENT)
+            .header("x-app-version", BML_APP_VERSION)
+            .header("accept", "application/json")
+            .build()
+        return client.newCall(request).execute().use { response ->
+            val body = response.body?.string() ?: return@use false
+            val json = try { JSONObject(body) } catch (_: Exception) { return@use false }
+            json.optBoolean("success") && json.optInt("code") == 99
+        }
+    }
+
     /**
      * Step 1 — initiate: POST with channel but no OTP.
      * Returns true when server responds with code 22 (OTP generated).