- Implemented a new `unsupportedBackend` in `backend_stub.go` to handle unsupported platforms.
- Created a `Service` struct in `service.go` to manage interactions with smart cards, including session management and identity reading.
- Added methods for reading identity, checking readiness, and authenticating with USIM applications.
- Introduced a `scriptedCard` for testing purposes in `service_test.go` to simulate card responses.
- Defined necessary types and error handling in `types.go` for better clarity and usability.
- Developed a `PCSCAdapter` in `vowifi/pcsc_adapter.go` to integrate PC/SC service with Wi-Fi calling functionalities.
- Added a new SVG icon for USB SIM readers in `public/sim-reader.svg`.
- Implemented tests to ensure correct functionality and error handling in various scenarios.
- Introduced a new field `custom_phone_number` in the CardPolicy model and database schema.
- Updated the API to handle custom phone number input, including validation and normalization.
- Modified the CardPolicyPanel component to allow users to set and save a custom phone number.
- Enhanced the settings API to include the custom phone number in responses and updates.
- Added tests to ensure the correct functionality of custom phone number handling.
- Removed hardcoded environment variable for VOCAT_ADDR in service files.
- Add eSIM notification management in `esim_notifications.go` with functions to retrieve, list, and remove notifications.
- Implement parsing logic for pending notifications and notification metadata.
- Create tests for eSIM notification parsing and request handling in `esim_notifications_test.go`.
- Introduce email message construction in `email_message.go` to securely format and send emails.
- Add tests for email message encoding and validation in `email_message_test.go`.
- Enhance the CardPolicyAPN component to manage APN configurations, including adding, editing, and deleting custom APNs.
- Implement UI for displaying and managing APN settings with appropriate validation and user feedback.
