a45c50ab7b
NewMockLogger/MockLogger move from the main `logging` package to a new `logging/logtest` sub-package, so the production `logging` package's import graph no longer pulls in testify — only consumers that import logtest do. testify stays in the module's go.mod (used by logtest and the library's own tests). Breaking import change for consumers: `logging.NewMockLogger` becomes `logtest.NewMockLogger`. The backend services that reference it are updated to the logtest import alongside their go.mod bump to this release. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>