ci: Add pre-commit hooks and GitHub Actions lint workflow

[rich7420]

Description

Add lint/format automation so every push and PR runs the same checks locally and in CI.

Included: Pre-commit (Ruff, ShellCheck, clang-format, generic hooks) + GitHub Actions workflow (.github/workflows/lint.yml) on push/PR to main and master. Config: pyproject.toml, .clang-format. Docs: docs/DEVELOPMENT.md; README Development section shortened with link and CI badge. .gitignore: .build/, .venv-lint/, Megatron-LM/, TransformerEngine/, models/. Excluded from hooks: Megatron-LM/, TransformerEngine/, .build/.

Code changes for hooks: Shell shebangs and quoting where needed; two baseline scripts excluded from ShellCheck. Python: fixes in pretrain_llama.py and similar (e.g. except Exception, zip(..., strict=True)).

Ignores / follow-up: Many pre-commit violations are currently ignored (Ruff per-file-ignores for tests/playground/baseline and temporarily distca/; rule-level ignores; ShellCheck excludes for a couple of baseline scripts) so CI is green. Plan is to gradually remove ignores and fix issues in follow-up (e.g. distca/ first, then tests/playground).

How to use: pip install pre-commit && pre-commit install. Manual: pre-commit run --all-files.

Checklist

• Pre-commit runs clean (excluding five internal plan docs)
• CI on push/PR to main and master
• Internal plan docs not referenced from other code/docs
• Follow-up: reduce ignores(a lot need to do) and fix violations (distca/ → tests/playground)

[rich7420]

@GindaChen could you help me to press workflow, please?