hscontrol/types: silence zerolog by default in tests

Tests were dumping megabytes of zerolog output on failure; silence
at init and let individual tests opt in via SetGlobalLevel when they need
log-driven assertions.

Updates #3157

hscontrol/util/zlog/init_test.go

@@ -0,0 +1,18 @@
+package zlog
+
+import "github.com/rs/zerolog"
+
+// init pins zerolog to TraceLevel for the zlog test binary.
+//
+// zlog's tests use zerolog.New(&buf) and assert on Info-level output. zerolog's
+// (*Logger).should() gates emission on the global level, so any global level
+// above Info would silently break the assertions.
+//
+// Today zlog does not transitively import hscontrol/types, so the test
+// silencing init() in hscontrol/types/testlog.go does not run in this binary.
+// This init defends against that changing in the future: if a future import
+// chain pulls in hscontrol/types, this file will still ensure trace-level
+// output is available for zlog's assertions.
+func init() {
+	zerolog.SetGlobalLevel(zerolog.TraceLevel)
+}