Remove local cache/build artifacts and generated outputs from tracked repo changes

[KooshaPari]

Summary

Remove accidental local cache/build artifacts and generated outputs from tracked repository changes so PRs contain only intended source and documentation updates.

Related PRs

• None yet

Acceptance Criteria

• Add/extend .gitignore patterns for local caches and generated files used in this repo's workflows.
• Remove already-tracked generated artifacts from git history tracking where appropriate.
• Update CI or pre-commit hooks to detect newly added tracked generated outputs and fail the run.
• Add a cleanup/reproducibility section to contributor docs showing how to regenerate outputs outside source control.
• Include one automated check that proves no forbidden paths are introduced in future PRs.