📝 docs: mkcert local HTTPS setup + Makefile cert target (ADR-0028 Phase B prep)

Makefile

@@ -0,0 +1,24 @@
+# dance-lessons-coach Makefile — minimal targets for local development.
+# This is a starter Makefile ; expand as needed (build, test, run, etc.).
+# Existing build/test workflows live in scripts/ and remain authoritative.
+
+CERT_DIR := ./certs
+
+.PHONY: help cert clean-cert
+
+help:
+	@echo "Available targets:"
+	@echo "  cert        Generate local-dev TLS certs via mkcert (cf. documentation/MKCERT.md)"
+	@echo "  clean-cert  Remove generated TLS certs"
+	@echo "  help        Show this help"
+
+cert: $(CERT_DIR)
+	@command -v mkcert >/dev/null 2>&1 || { echo >&2 "mkcert not found. See documentation/MKCERT.md to install."; exit 1; }
+	mkcert -cert-file $(CERT_DIR)/dev-cert.pem -key-file $(CERT_DIR)/dev-key.pem localhost 127.0.0.1 ::1
+	@echo "Certs ready at $(CERT_DIR)/. Cf. documentation/MKCERT.md for usage."
+
+$(CERT_DIR):
+	mkdir -p $(CERT_DIR)
+
+clean-cert:
+	rm -rf $(CERT_DIR)