refactor: rebuild desktop app with Tauri

crates/semble-core/src/error.rs

@@ -0,0 +1,48 @@
+//! Errors shared by indexing, persistence, model loading, and retrieval.
+
+use std::path::PathBuf;
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("source does not exist: {0}")]
+    SourceMissing(PathBuf),
+    #[error("source is not a directory: {0}")]
+    SourceNotDirectory(PathBuf),
+    #[error("source path escapes the allowed root: {0}")]
+    UnsafePath(PathBuf),
+    #[error("unsupported repository URL: {0}")]
+    UnsupportedUrl(String),
+    #[error("git operation failed: {0}")]
+    Git(String),
+    #[error("model asset error: {0}")]
+    ModelAsset(String),
+    #[error("model inference error: {0}")]
+    Model(String),
+    #[error("index is empty: {0}")]
+    EmptyIndex(PathBuf),
+    #[error("invalid request: {0}")]
+    InvalidRequest(String),
+    #[error("persisted index is incompatible or corrupt: {0}")]
+    CorruptIndex(String),
+    #[error("I/O error at {path}: {source}")]
+    Io {
+        path: PathBuf,
+        #[source]
+        source: std::io::Error,
+    },
+    #[error(transparent)]
+    Json(#[from] serde_json::Error),
+    #[error("serialization error: {0}")]
+    Serialization(String),
+}
+
+impl Error {
+    pub(crate) fn io(path: impl Into<PathBuf>, source: std::io::Error) -> Self {
+        Self::Io {
+            path: path.into(),
+            source,
+        }
+    }
+}
+
+pub type Result<T> = std::result::Result<T, Error>;