Bug: [BUG] payout routing for Sepa transactions result in a 4xx error



### Bug Description

Creating payout transactions for SEPA are resulting in a 4xx error with below message.

```
{
    "error": {
        "type": "invalid_request",
        "message": "No eligible connector was found for the current payment method configuration",
        "code": "IR_39"
    }
}
```

### Expected Behavior

Payout transactions for SEPA should be routed through eligible connectors.

### Actual Behavior

Payout routing fails to get an eligible connector for SEPA bank transfers.

### Steps To Reproduce

1. Create Wise connector
2. Try creating a SEPA payout
3. It should throw below error response

```
{
    "error": {
        "type": "invalid_request",
        "message": "No eligible connector was found for the current payment method configuration",
        "code": "IR_39"
    }
}
```


### Context For The Bug

This is happening due to a mismatch in what is configured for available payment methods during MCA creation - which stores `sepa` as payment method type in DB - vs what is used during payout routing - which uses `sepa_bank_transfer` for SEPA transactions.

MCA creation on dashboard uses a wasm build which contains the info for enabling the right payment method types for payouts. It is configured to use `sepa` instead of `sepa_bank_transfer` (which is being used in the payout flow).

There was an activity to rename `Sepa` to `SepaBankTransfer` recently. More details [here](https://github.com/juspay/hyperswitch/pull/7575).


### Have you spent some time checking if this bug has been raised before?

- [x] I checked and didn't find a similar issue

### Have you read the Contributing Guidelines?

- [x] I have read the [Contributing Guidelines](https://github.com/juspay/hyperswitch/blob/main/docs/CONTRIBUTING.md)

### Are you willing to submit a PR?

Yes, I am willing to submit a PR!
diff --git a/crates/euclid/src/enums.rs b/crates/euclid/src/enums.rs
index cfd410f0d3b..22fb997530c 100644
--- a/crates/euclid/src/enums.rs
+++ b/crates/euclid/src/enums.rs
@@ -123,7 +123,7 @@ pub enum MandateType {
 pub enum PayoutBankTransferType {
     Ach,
     Bacs,
-    Sepa,
+    SepaBankTransfer,
 }
 
 #[cfg(feature = "payouts")]

## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [x] Bugfix

## Description
This PR fixes SEPA payout routing failures by updating database configurations to use `sepa_bank_transfer` instead of `sepa` for payout flows. This was missed as part of the refactoring in https://github.com/juspay/hyperswitch/pull/7575

### Additional Changes

- [ ] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

## Motivation and Context
SEPA payout transactions were failing with IR_39 error "No eligible connector was found" due to mismatch between MCA creation (storing `sepa`) and payout routing (expecting `sepa_bank_transfer`).

## How did you test it?
<details>
    <summary>1. Create payout MCA with correct payment method types</summary>

cURL

    curl --location --request POST 'http://localhost:8080/account/merchant_1753677780/connectors' \
        --header 'Content-Type: application/json' \
        --header 'Accept: application/json' \
        --header 'api-key: dev_fz41TYdizfMTp52AI6fK3rVBgJBOCBTDPJb5L60zwrwjWtl1L4Kowt6vjDDMtlHh' \
        --data '{"connector_type":"payout_processor","connector_name":"adyenplatform","connector_account_details":{"auth_type":"HeaderKey","api_key":"--REDACTED--"},"test_mode":true,"disabled":false,"connector_webhook_details":{"merchant_secret":"--REDACTED--"},"metadata":{"city":"NY","unit":"245","source_balance_account":"--REDACTED--"},"payment_methods_enabled":[{"payment_method":"card","payment_method_types":[{"payment_method_type":"credit","payment_experience":null,"card_networks":null,"accepted_currencies":null,"accepted_countries":null,"minimum_amount":1,"maximum_amount":68607706,"recurring_enabled":true,"installment_payment_enabled":true},{"payment_method_type":"debit","payment_experience":null,"card_networks":null,"accepted_currencies":null,"accepted_countries":null,"minimum_amount":1,"maximum_amount":68607706,"recurring_enabled":true,"installment_payment_enabled":true}]},{"payment_method":"bank_transfer","payment_method_types":[{"payment_method_type":"sepa_bank_transfer","payment_experience":null,"card_networks":null,"accepted_currencies":null,"accepted_countries":null,"minimum_amount":1,"maximum_amount":68607706,"recurring_enabled":true,"installment_payment_enabled":true}]}]}'

Response

    {"connector_type":"payout_processor","connector_name":"adyenplatform","connector_label":"adyenplatform_IN_default","merchant_connector_id":"mca_YloX72LoDYUkHncGiPPZ","profile_id":"pro_33khv5M29zLwL9wtxsqw","connector_account_details":{"auth_type":"HeaderKey","api_key":"AQ*********************************************************************************************************************************************************************aH"},"payment_methods_enabled":[{"payment_method":"card","payment_method_types":[{"payment_method_type":"credit","payment_experience":null,"card_networks":null,"accepted_currencies":null,"accepted_countries":null,"minimum_amount":1,"maximum_amount":68607706,"recurring_enabled":true,"installment_payment_enabled":true},{"payment_method_type":"debit","payment_experience":null,"card_networks":null,"accepted_currencies":null,"accepted_countries":null,"minimum_amount":1,"maximum_amount":68607706,"recurring_enabled":true,"installment_payment_enabled":true}]},{"payment_method":"bank_transfer","payment_method_types":[{"payment_method_type":"sepa_bank_transfer","payment_experience":null,"card_networks":null,"accepted_currencies":null,"accepted_countries":null,"minimum_amount":1,"maximum_amount":68607706,"recurring_enabled":true,"installment_payment_enabled":true}]}],"connector_webhook_details":{"merchant_secret":"--REDACTED--","additional_secret":null},"metadata":{"city":"NY","unit":"245","source_balance_account":"--REDACTED--"},"test_mode":true,"disabled":false,"frm_configs":null,"business_country":null,"business_label":null,"business_sub_label":null,"applepay_verified_domains":null,"pm_auth_config":null,"status":"active","additional_merchant_data":null,"connector_wallets_details":null}

</details>


<details>
    <summary>2. Process SEPA payout</summary>

cURL

    curl --location --request POST 'http://localhost:8080/payouts/create' \
        --header 'Accept-Language: fr' \
        --header 'Content-Type: application/json' \
        --header 'api-key: dev_fz41TYdizfMTp52AI6fK3rVBgJBOCBTDPJb5L60zwrwjWtl1L4Kowt6vjDDMtlHh' \
        --data '{"amount":1,"currency":"EUR","customer_id":"cus_EqPGPc4wDSFQaccgd1LH","description":"Its my first payout request","payout_type":"bank","priority":"instant","payout_method_data":{"bank":{"iban":"FR6410096000403534259742Y90"}},"connector":["adyenplatform"],"billing":{"address":{"line1":"Raadhuisplein","line2":"92","city":"Hoogeveen","state":"FL","zip":"7901 BW","country":"NL","first_name":"John","last_name":"Doe"}},"entity_type":"Individual","recurring":true,"metadata":{"ref":"123"},"confirm":true,"auto_fulfill":true,"profile_id":"pro_33khv5M29zLwL9wtxsqw"}'

Response

    {"payout_id":"payout_e6ksBET8el30f3dx0h3c","merchant_id":"merchant_1753677780","merchant_order_reference_id":null,"amount":1,"currency":"EUR","connector":"adyenplatform","payout_type":"bank","payout_method_data":{"bank":{"iban":"FR641*****************42Y90","bank_name":null,"bank_country_code":null,"bank_city":null,"bic":null}},"billing":{"address":{"city":"Hoogeveen","country":"NL","line1":"Raadhuisplein","line2":"92","line3":null,"zip":"7901 BW","state":"FL","first_name":"John","last_name":"Doe"},"phone":null,"email":null},"auto_fulfill":true,"customer_id":"cus_EqPGPc4wDSFQaccgd1LH","customer":{"id":"cus_EqPGPc4wDSFQaccgd1LH","name":"John Nether","email":null,"phone":"6168205362","phone_country_code":"+1"},"client_secret":"payout_payout_e6ksBET8el30f3dx0h3c_secret_v3aGZrFuRRmGgsUx6IzH","return_url":null,"business_country":null,"business_label":null,"description":"Its my first payout request","entity_type":"Individual","recurring":true,"metadata":{"ref":"123"},"merchant_connector_id":"mca_YloX72LoDYUkHncGiPPZ","status":"initiated","error_message":null,"error_code":null,"profile_id":"pro_33khv5M29zLwL9wtxsqw","created":"2025-07-28T04:45:54.833Z","connector_transaction_id":"38E99D67SA9RK52A","priority":"instant","payout_link":null,"email":null,"name":"John Nether","phone":"6168205362","phone_country_code":"+1","unified_code":null,"unified_message":null,"payout_method_id":"pm_uQh6dJST71ojH7qKyqfb"}

</details>

## Checklist
<!-- Put an `x` in the boxes that apply -->

- [x] I formatted the code `cargo +nightly fmt --all`
- [x] I addressed lints thrown by `cargo clippy`
- [x] I reviewed the submitted code
- [ ] I added unit tests for my changes where possible