# Lessons

Patterns observed during development of this repo. Three or more entries on the same pattern → promote to CONTEXT.md (or the relevant instruction file) as a standing rule.

**Graduation rule:** When three or more entries cover the same pattern, the human reviews and promotes it to the appropriate standing location: `CONTEXT.md` for domain-level principles, `core/instructions/coding.md` for coding conventions, `core/instructions/git.md` for git conventions, or `core/instructions/testing.md` for testing conventions. The graduated entries are marked `[graduated → target file]` rather than deleted (audit trail).

**Who writes here:** The session-handoff skill (Chunk 3) prompts LESSONS.md extraction before closing a session. The human may also write directly.

**What belongs here:** Non-obvious observations — a rule that was misapplied, a pattern that caused friction, a decision that turned out wrong in practice. Not summaries of what was built (that's git history) or planned changes (that's issues).