[dajiaohuang]

Summary

Pass the configured output directory when generating the HTML page in the Python 3 visualization script. Without this argument, using -ht/--html raises a TypeError after the image and legend are written.

Fixes #36.

Validation

• Ran the Python 3 script against a minimal two-call trace with -ht and -of; it exited 0 and wrote the requested HTML page, image, and legend under the output directory.
• Parsed the modified script with Python's AST parser.
• git diff --check passed.

The focused visualization run used a minimal local pylab import stub because that optional plotting module is not installed in the validation environment. A full native build is unavailable because the DynamoRIO submodule is uninitialized and the repository's legacy toolchains are absent.