[codex] Add portfolio demo positioning

[Oranquelui]

Summary

• Adds portfolio-oriented README framing for Patchrail as a representative engineering project.
• Adds a 3-minute demo guide focused on verify, review-queue, and packet evidence.
• Adds Japanese resume/interview positioning notes and updates the supervised agent rollout case study for v0.2 verification.

Scope

Docs-only stacked PR on top of the v0.2 verification packet branch. No code changes.

Test Plan

• pytest tests/test_project_metadata.py -q
• pytest -q