Add wfctl infra bootstrap implementation plan

11 tasks: sensitive masking, GitHub secrets provider, secret generators,
secrets config parsing, bootstrap command, output template resolution,
auto-bootstrap in apply, plan/apply masking, DO driver sensitive keys,
DnD deploy simplification, engine release.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: intel352