feat(embedding,vision): candle embeddings with offline fallback, on-demand clipboard vision capture, and concurrency audit

server/src/handlers/utils.rs

@@ -14,6 +14,19 @@ pub fn now_secs() -> u64 {
         .as_secs()
 }
 
+pub fn validate_safe_path(path_str: &str) -> crate::error::Result<std::path::PathBuf> {
+    let path = std::path::Path::new(path_str);
+    for component in path.components() {
+        if component == std::path::Component::ParentDir {
+            return Err(crate::error::AppError::BadRequest(format!(
+                "Path traversal forbidden: '{}' contains relative parent directory components ('..')",
+                path_str
+            )));
+        }
+    }
+    Ok(path.to_path_buf())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;