perf(scan): skip extensionless files by default

senbei-cli/src/main.rs

@@ -106,7 +106,7 @@ fn print_help() {
     );
     println!(
         "  --scan-all   probe every file in a folder, including ones the scan\n\
-         \x20              pre-filter skips (under 4128 bytes, or a bulk-asset\n\
-         \x20              extension like .ab/.xml/.acb). Much slower on game trees."
+         \x20              pre-filter skips (under 4128 bytes, extensionless,\n\
+         \x20              or a bulk-asset extension). Much slower on large trees."
     );
 }