chore: add security policy and standardize pre-commit and release config

[anmolnagpal]

Summary

• Add SECURITY.md with vulnerability reporting policy
• Add CONTRIBUTING.md with development guidelines
• Add .releaserc.json for semantic-release automation
• Update .editorconfig to match industry standards
• Update .pre-commit-config.yaml to antonbabenko/pre-commit-terraform v1.105.0
• Set provider: none in tf-checks workflow (skip cloud auth for validate-only)
• Fix version constraints if needed

Test plan

• Verify pre-commit hooks pass locally
• Verify CI checks pass
• Verify terraform validate succeeds