[devops] Pre-commit v2 + CI governance — fork sync, PR awareness, data accuracy

[enioxt]

TASK-120 (new)

Unified pre-commit hook combining best practices from egos-lab, carteira-livre, and br-acc:

• Security scan (secrets, .env, large files)
• Python syntax + ruff lint
• Frontend crash prevention (unsafe array access, console.log flood)
• Data accuracy (141M/MIT detection)
• Upstream fork sync check (World-Open-Graph/br-acc)
• GitHub PR/Issue awareness
• TASKS.md sync warning
• Integration into /start and /end workflows
• Auto-sync TASKS.md ↔ GitHub Issues

Files: scripts/pre-commit-v2.sh (installed to .git/hooks/pre-commit)
Priority: P1
Area: DevOps / Governance