docs: remove stale pitfalls guide and tidy AGENTS.md

AGENTS.md

@@ -4,12 +4,11 @@ See [README.md](./README.md) for basic info, language docs, and examples.
 
 ## General principles
 
-- The codebase is the source of truth — verify against current code before asserting.
+- The codebase is the source of truth. Verify against current code before asserting.
 - Don't web-search Casa specifics; this repo is the only authoritative source.
 - When language features or stdlib functions change, update the corresponding
   documentation, examples, and tests.
 - Never mention Claude or AI usage
-- Always use caveman skill
 
 ## Code conventions
 
@@ -33,13 +32,15 @@ See [README.md](./README.md) for basic info, language docs, and examples.
 
 ## Agent skills
 
+- Always use `caveman` skill
+- Use `tdd` skill whenever making new features or functionality changes
+
 Always load the relevant doc when the matching workflow comes up:
 
 - **Git** — `docs/agents/git.md`
 - **Testing** — `docs/agents/testing.md`
 - **Review** — `docs/agents/review.md`
 - **Examples** — `docs/agents/examples.md`
-- **Pitfalls** — `docs/agents/pitfalls.md` (known Casa gotchas with workarounds)
 - **Issue tracker** — `docs/agents/issue-tracker.md`
 - **Triage labels** — `docs/agents/triage-labels.md`
 - **Domain docs** — `docs/agents/domain.md`