Add a Host trait and move DB/model commands off Tauri (#558)

crates/yaak-commands/src/error.rs

@@ -0,0 +1,30 @@
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error(transparent)]
+    Yaak(#[from] yaak::Error),
+
+    #[error(transparent)]
+    Model(#[from] yaak_models::error::Error),
+
+    #[error(transparent)]
+    Plugin(#[from] yaak_plugins::error::Error),
+
+    #[error(transparent)]
+    Crypto(#[from] yaak_crypto::error::Error),
+
+    #[error(transparent)]
+    Template(#[from] yaak_templates::error::Error),
+
+    #[error("JSON error: {0}")]
+    Json(#[from] serde_json::Error),
+
+    #[error("I/O error: {0}")]
+    Io(#[from] std::io::Error),
+
+    #[error("{0}")]
+    Generic(String),
+}
+
+pub type Result<T> = std::result::Result<T, Error>;