ACI-008: Style Rules vs Architecture Rules

Thesis

Generic code style rules in CLAUDE.md do not change agent behavior because the agent already knows them. Project-specific architecture rules change behavior on every session. The progression from style rules to architecture rules is a measurable maturity signal in any agentic codebase.

Story

All three repos in this study started their CLAUDE.md files with detailed Elixir code style rules. Intent's March 2025 version had 15 bullet points: use @moduledoc, prefer pipe operators, handle errors with pattern matching, use 2-space indentation. MeetZaya's April 2025 version had the same list plus additional functional programming principles. These rules were well-written, correct, and entirely useless -- Claude already knows how to write idiomatic Elixir.