feat(cli): add agent-safe exec and log filters

[robertohluna]

Summary

• add Northflank-style --cmd / --shell-cmd flags to miosa sandbox exec and miosa sandbox run
• add top-level miosa logs explicit deployment targeting plus --lines, text, and regex filters
• document the agent-safe exec/log workflows in README and miosa capabilities --json

Verification

• npm test
• npm run typecheck
• npm run build

Notes

• Metrics and forward-all are intentionally not faked here; they need backend-backed resource metrics and multi-resource forwarding models.