Run make test once so a failing test fails the build (closes #101)

make test retried a failed go test run with go test -v, and when the
retry passed, make test, make check and the Docker build all reported
success, hiding real failures. It now runs go test once, keeping
-timeout 120s, -race and -cover.

Model: opus-5-5

Makefile

@@ -31,7 +31,7 @@ fmt-check:
 	@test -z "$$(gofmt -l .)" || (echo "Files not formatted:" && gofmt -l . && exit 1)
 
 test: ensure-web-dist
-	go test -timeout 120s -race -cover ./... || go test -timeout 120s -race -v ./...
+	go test -timeout 120s -race -cover ./...
 
 # check runs all validation without making changes
 # Used by CI and Docker build — fails if anything is wrong