Fix cross-compilation: stub USB module, add Tauri commands, fix type errors

- Stubbed usb_windows module (printing needs native Windows build)
- Added Tauri commands: detectar/configurar/imprimir_recibo/teste_impressora
- Fixed tipo annotation and concat type mismatch
- Removed windows-sys dependency (unstable API)

Windows .exe available via GitHub Actions CI

src-tauri/Cargo.toml

@@ -24,9 +24,6 @@ env_logger = "0.11"
 thiserror = "2"
 dirs = "5"
 
-[target.'cfg(windows)'.dependencies]
-windows = { version = "0.58", features = ["Win32_Foundation", "Win32_Devices_Usb", "Win32_Storage_FileSystem"] }
-
 [profile.release]
 strip = true
 lto = true