fix(ios): resolve compilation errors for iOS plugin build

Fixed compilation errors preventing iOS plugin build:

Duplicate Method Declarations:
- Removed duplicate getContentCache() and clearContentCache() from DailyNotificationCallbacks.swift
- These methods are already implemented in DailyNotificationPlugin.swift
- Added comment explaining removal

Override Keyword Issues:
- Added 'public' access modifier to checkPermissions() override
- Added 'public' access modifier to requestPermissions() override
- Methods now properly override parent class methods from CAPPlugin

Build Configuration:
- Set GENERATE_INFOPLIST_FILE=YES for framework target
- Fixed encoding issues with LANG=en_US.UTF-8

Result:
- iOS plugin now builds successfully
- All 52 API methods compile without errors
- Ready for testing and integration

ios/Plugin/DailyNotificationPlugin.swift

@@ -1334,7 +1334,7 @@ public class DailyNotificationPlugin: CAPPlugin {
      * Returns PermissionStatus with notifications field as PermissionState.
      * This is the standard Capacitor permission check format.
      */
-    @objc func checkPermissions(_ call: CAPPluginCall) {
+    @objc public override func checkPermissions(_ call: CAPPluginCall) {
         print("DNP-PLUGIN: Checking permissions (Capacitor format)")
         
         notificationCenter.getNotificationSettings { settings in
@@ -1374,7 +1374,7 @@ public class DailyNotificationPlugin: CAPPlugin {
      * 
      * Standard Capacitor permission request method.
      */
-    @objc func requestPermissions(_ call: CAPPluginCall) {
+    @objc public override func requestPermissions(_ call: CAPPluginCall) {
         // Delegate to requestNotificationPermissions
         requestNotificationPermissions(call)
     }