docs: add ultraplan for issues #386, #378, #377

Comprehensive analysis and execution plan covering:
- Issue #386: gitleaks failure (root cause + fix)
- Issue #378: multi-failure CI (rust-ci, mirrors, Hypatia, Codeac)
- Issue #377: CWE-377 in personal-sysadmin scripts
- Binding standards: RSR template, CLAUDE.md, Hospital Model
- Execution order, acceptance criteria, risk assessment

Co-authored-by: arena-agent <297053741+arena-agent@users.noreply.github.com>

Author: hyperpolymath