Update CLAUDE.md with learnings

CLAUDE.md is the project's institutional knowledge — the things a new developer (or a new Claude session) needs to know that aren't obvious from the code itself. The goal is to keep it concise, current, and high-signal.

What belongs in CLAUDE.md

Include information that saves future sessions from re-discovering things the hard way:

• Conventions and philosophy — e.g., "Prefer composition over inheritance", "No backwards compatibility unless explicitly requested"
• Non-obvious gotchas — Things that cause repeated bugs or confusion
• Build/test/run commands — How to run, test, lint, deploy
• Project structure — Key directories and their purpose, especially if the layout is non-standard
• Recent significant changes — New capabilities, major refactors, or architectural shifts that change how the project works

What does NOT belong

Skip anything that's either ephemeral or derivable from the code:

• Bug fix details — the fix is in the code, the context is in the commit message
• Implementation details obvious from reading the source
• Temporary workarounds that will be removed soon
• One-off decisions that won't recur

Rule of thumb: Would you tell a new developer this on their first day? If yes, add it. If it's just details about today's work, skip it.

Instructions

1. Read CLAUDE.md — If it exists, understand what's already documented so you don't duplicate. If it doesn't exist, you'll create it.
2. Review recent work — Run git log --oneline -20 and git diff HEAD~5..HEAD --stat to identify significant changes. Look for patterns: new scripts, moved directories, changed conventions, recurring issues.
3. Extract meta learnings — From the recent work and the current conversation, identify anything that fits the "what belongs" criteria above.
4. Update conservatively — Keep CLAUDE.md under 300 lines. If adding new content pushes it over, remove outdated entries first. Prefer updating existing sections over adding new ones.

Output

After updating, summarize:

• What was added/changed
• What was removed (if anything)
• Current line count