Structured logger shared across the server. JSON output defaults to stderr;
entry points call initLogging() to let B2_LOG_FILE replace stderr with an
owner-only append file destination.
Keeping logs off stdout preserves the stdio transport's MCP protocol channel.
Sensitive fields (auth tokens, B2 keys) are redacted at the logger
level — callers can pass full objects without worrying about leaks.
Structured logger shared across the server. JSON output defaults to stderr; entry points call initLogging() to let B2_LOG_FILE replace stderr with an owner-only append file destination.
Keeping logs off stdout preserves the stdio transport's MCP protocol channel.
Sensitive fields (auth tokens, B2 keys) are redacted at the logger level — callers can pass full objects without worrying about leaks.