memory-md-system-architecture-belongs-in-topic-files

The System Architecture section in MEMORY.md was 5.4KB duplicating architecture.md — a direct Law 1 (Zero Redundancy) violation and the primary cause of the size breach. The correct pattern is lean pointers (~1.2KB) in MEMORY.md with full infrastructure detail in architecture.md. Every future addition to MEMORY.md must ask: does this belong in a topic file instead?