logger fixes

include/zinnia/print.h

@@ -34,6 +34,9 @@ void log_vwrite(enum log_level level, const char* message, va_list args);
 // Like log_vwrite(), but prepends a `prefix` to the message.
 void log_vwrite_prefixed(enum log_level level, const char* prefix, const char* message, va_list args);
 
+// Passes every record currently in the log buffer to `callback`.
+void log_replay(log_fn_t callback, void* ctx);
+
 #ifndef pr_fmt
 #define pr_fmt(fmt) fmt
 #endif