[Epic] Make the Code Review Engineer a real, differentiated employee #10

Context

AgentOS markets a marketplace of specialized AI employees, but exploration showed the employee types aren't actually differentiated: Code Review Engineer, Customer Support, and Secretary run the identical container with the identical code and skill set — the role is just a string env var. The template fields that would make a role distinct (system_prompt, allowed_actions) are parsed but ignored, and the "5-layer enforcement moat" from the docs is entirely unbuilt.

Decision: go deep on one role rather than add more undifferentiated shells. Turn the Code Review Engineer into a genuinely real employee — behavior driven by its template, boundaries provably enforced, autonomous, and memory-backed. The engine built here (template → runtime) is also what would make any future breadth or marketplace play cheap.

Phases — build order A → B → D → C

• Phase A — Template-driven agent runtime #6 — Phase A: Template-driven agent runtime
• Phase B — Enforced action policy (trust moat) #7 — Phase B: Enforced action policy (trust moat)
• Phase D — Agent memory & work log #8 — Phase D: Agent memory & work log
• Phase C — Autonomous PR review #9 — Phase C: Autonomous PR review

Notes

• The four phases share one migration backend/migrations/004_code_review_engineer.sql (also update schema.sql).
• Runs locally on Docker Desktop; ~5 days total for one engineer.