fix: remove relative path fallback in findConvertScript, rely on PATH only

src/Roux/Server.hs

@@ -479,7 +479,11 @@ findConvertScript = do
     mPath <- findExecutable "convert-to-cooklang"
     case mPath of
         Just p -> pure p
-        Nothing -> makeAbsolute "scripts/convert-to-cooklang"
+        Nothing ->
+            ioError $
+                userError $
+                    "convert-to-cooklang not found on PATH. "
+                        <> "Install it to /usr/local/bin/convert-to-cooklang or add it to PATH."
 
 -- | Write a temporary YAML config for the subprocess.
 writeConvertConfig :: FilePath -> AnthropicConfig -> IO ()