ACI-007: Cross-Project Contamination

Thesis

When a developer uses the same AI coding agent across multiple projects, the agent imports patterns, architectures, and domain concepts from one project into another. This cross-contamination is invisible until it causes bugs or confusion, and it requires explicit guardrails in CLAUDE.md to prevent.

Story

Lamplight is an interactive narrative platform built on Elixir/Phoenix. In September 2025, after several months of development, the CLAUDE.md gained a section titled "Important: Subagent and Cross-Project Guidelines" with three subsections: Subagent Usage, Project Context, and Cross-Contamination Prevention.