feat: initial project structure and generate API types

Initialized `package.json`, add tsup build config (CJS/ESM/DTS), wire up
full Makefile targets (lint/test/check/build), add missing BadRequest
response component to OpenAPI spec, generate TypeScript types from spec,
configure biome to exclude generated files, and add `@types/ws`

Makefile

@@ -0,0 +1,29 @@
+# Makefile
+.PHONY: generate lint test test-integration check build
+
+SPEC_URL = "https://raw.githubusercontent.com/wrennhq/wrenn/refs/heads/main/internal/api/openapi.yaml"
+SPEC_PATH = "api/openapi.yaml"
+
+generate:
+	@echo "Fetching latest OpenAPI spec from Git repo..."
+	mkdir -p api
+	curl -fsSL $(SPEC_URL) -o $(SPEC_PATH)
+	@echo "Generating TypeScript types..."
+	mkdir -p src/models
+	pnpm generate
+
+lint:
+	pnpm exec biome check .
+
+test:
+	pnpm vitest run --exclude tests/integration
+
+test-integration:
+	pnpm test:integration
+
+check:
+	$(MAKE) lint
+	$(MAKE) test
+
+build:
+	pnpm build