fix: use deploy project cwd

src/sync.rs

@@ -38,7 +38,10 @@ pub fn upload(session: &mut Session, source: &Path, target: &str) -> Result<Stat
         } else if source.is_file() {
             upload_file(session, source, target).await
         } else {
-            bail!("sync source '{}' does not exist", source.display());
+            bail!(
+                "sync source '{}' does not exist (relative paths are resolved against project workdir)",
+                source.display()
+            );
         }
     })
 }