ww: print final status for explicit test failures

docs/spec.md

@@ -790,6 +790,19 @@ linker, and other build failures retain their diagnostic standard-error
 channel; build-action stdout and stderr remain separate. Parallel products own
 independent captures and are still emitted in canonical product order.
 
+After those ordered results, an ordinary explicit `ww test` request that records
+an attributable setup, build, or execution failure emits exactly one standalone
+`FAIL\n` on standard output. The line is command-owned: it follows even a later
+successful package result, and a single explicit directory, recursive or dotted
+directory, or raw source file is sufficient. Runtime nonzero exit, signal,
+timeout, or executable-start failure all set that status. Filters, list mode,
+and the private execution of a retained test keep the same rule. Bare implicit
+current-directory `ww test`, `-c`, `-S`, build requests, CLI usage/shape or
+output preflight, publication-only failure, capture-only failure, cleanup-only
+failure, and later direct execution of a retained binary do not emit it. The
+marker changes no capture, diagnostic, executable, package/import/action
+identity, publication decision, or persistent byte.
+
 The coordinator does not change its own cwd or environment. Parallel products
 receive independent child environments and each uses its own source directory.
 Relative ordinary files, `testdata`, and writes resolve there for every