SHX fonts: review fixes (search the current folder for a bare drawing name, one lock for the font cache generation, no split_paths on wasm, MTEXT \U+ upper case as the layout, a point budget for repeated linetype shapes, web picks report skipped files and cap bytes read at once)

crates/engine/src/cmd/file.rs

@@ -336,6 +336,8 @@ fn read_bytes(bytes: &[u8], name: &str, path: Option<String>) -> Result<ReadFile
     let path = path.filter(|p| is_drawing_file(p));
     // The SHX fonts its text styles name are looked for beside the drawing too.
     if let Some(dir) = path.as_deref().and_then(|p| std::path::Path::new(p).parent()) {
+        // A bare file name is in the current folder.
+        let dir = if dir.as_os_str().is_empty() { std::path::Path::new(".") } else { dir };
         cadcraft_fonts::shx::add_drawing_dir(&std::path::absolute(dir).unwrap_or_else(|_| dir.to_path_buf()));
     }
     Ok(ReadFile { drawing, binary_dxf: cadcraft_dxf::is_binary(bytes), name: name.to_string(), path })