Refactor: Extract SyncResolverApi interface and SyncDeviceManager class

[guiyanakuang]

Background

SyncResolver mixes two concerns:

1. Complex connection resolution logic (telnet, heartbeat, token verification)
2. Simple device management delegates (DAO calls, API notifications)

It also has no interface, making it harder to mock and violating dependency inversion.

Changes

Extract SyncResolverApi interface

• New interface with a single emitEvent(event: SyncEvent) method
• SyncResolver implements the interface
• GeneralSyncManager and Koin bindings depend on the interface

Extract SyncDeviceManager class

Move 7 device management methods into a focused class with only 3 dependencies:

• updateAllowSend, updateAllowReceive, updateNoteName
• showToken, notifyExit, markExit, removeDevice

Split tests

• Move 11 device management tests from SyncResolverTest to SyncDeviceManagerTest
• SyncDeviceManagerTest mocks only 3 deps instead of 10+