feat: enhance event display with color-coded parsing and structured UI

- Add color-coded event backgrounds based on event types (success/error/warning/info)
- Parse JSON events into structured key-value display instead of raw JSON
- Extract event UI logic into separate stateful widgets for consistency
- Add event management features: copy, clear, counter, proper lifecycle
- Support loan-specific event types (approved, disbursed, rejected, etc.)
- Implement proper event stream listening with start/stop lifecycle
- Maintain consistent architecture between ConnectScreen and SILoansPage

Author: dporwal-shipit

loans/ios/Classes/ScLoanEventsHandler.swift

@@ -1,5 +1,6 @@
 import Foundation
 import Flutter
+import Loans
 
 class ScLoanEventsHandler: NSObject {
 
@@ -19,7 +20,7 @@ class ScLoanEventsHandler: NSObject {
 
     private func setupNotificationListener() {
         NotificationCenter.default.addObserver(
-            forName: Notification.Name("scloans_notification"),
+            forName: ScLoan.scLoansNotificationName,
             object: nil,
             queue: .main
         ) { [weak self] notification in
@@ -30,7 +31,7 @@ class ScLoanEventsHandler: NSObject {
     private func handleNotification(_ notification: Notification) {
         guard let eventStreamHandler = eventStreamHandler,
               let userInfo = notification.userInfo,
-              let jsonString = userInfo["payload_str"] as? String else { return }
+              let jsonString = userInfo[ScLoanNotification.strigifiedPayloadKey] as? String else { return }
 
         eventStreamHandler.sendEvent(jsonString)
     }

scgateway/ios/Classes/ScgatewayEventsHandler.swift

@@ -1,5 +1,6 @@
 import Foundation
 import Flutter
+import SCGateway
 
 class ScgatewayEventsHandler: NSObject {
 
@@ -19,7 +20,7 @@ class ScgatewayEventsHandler: NSObject {
 
     private func setupNotificationListener() {
         NotificationCenter.default.addObserver(
-            forName: Notification.Name("scg_notification"),
+            forName: SCGateway.scgNotificationName,
             object: nil,
             queue: .main
         ) { [weak self] notification in
@@ -30,7 +31,7 @@ class ScgatewayEventsHandler: NSObject {
     private func handleNotification(_ notification: Notification) {
         guard let eventStreamHandler = eventStreamHandler,
               let userInfo = notification.userInfo,
-              let jsonString = userInfo["payload_str"] as? String else { return }
+              let jsonString = userInfo[SCGNotification.strigifiedPayloadKey] as? String else { return }
 
         eventStreamHandler.sendEvent(jsonString)
     }