Add HTTP server tests and clean generated artifacts

[nipun172006]

Summary

• replace coursework-style copy with recruiter-focused engineering documentation
• add 10 dependency-free unit tests and a CI workflow
• ignore runtime uploads and remove previously committed generated upload files
• remove empty command-output artifacts and redundant root-level image copies
• retain the in-project large transfer fixture; do not rewrite Git history

Validation

• python3 -m unittest discover -s tests -v (10 tests passed)