fix(timestamp): log without undefined values (0xAA)

src/zlog.zig

@@ -58,7 +58,7 @@ fn log_timestamp(writer: anytype) void {
     const curtime = c_time.time(null);
     const tm = c_time.localtime(&curtime);
 
-    var buffer: [32]u8 = undefined;
+    var buffer: [16]u8 = undefined;
     _ = c_time.strftime(@ptrCast(&buffer), 32, "%F %R", tm);
     writer.print("[{s}] ", .{buffer}) catch return;
 }