docs: update README.md and AGENTS.md for new files

Update documentation to reflect new project structure
and files created for test coverage enhancement.

README.md:
- Add STATUS.md link to documentation table
- Add JOURNAL.md link to documentation table
- STATUS.md: Manager-facing status report
- JOURNAL.md: AI agent memory and ADRs

AGENTS.md:
- Document STATUS.md purpose and maintenance
- Document JOURNAL.md purpose (AI memory, ADRs)
- Add tests/system/ directory to project structure
- Clean up obsolete file references
- Update documentation structure section

These changes ensure all team members (human and AI)
understand the purpose and location of key files.

💘 Generated with Crush

Assisted-by: GLM-5 via Crush <crush@charm.land>

README.md

@@ -10,6 +10,8 @@
 ### 📋 Documentation Files
 | File | Purpose |
 |------|---------|
+| **STATUS.md** | 📊 Project status report (manager quick-glance) |
+| **JOURNAL.md** | 📝 AI memory, ADRs, lessons learned (append-only) |
 | **AGENTS.md** | ⚡ START HERE - Current status + requirements |
 | **PRD.md** | Complete product requirements |
 | **docs/TEST-COVERAGE.md** | Test suite details and coverage |