The preamble is discussing who is creating the constitution and why. It does not say it only applies to certain individuals. I don't see how you can use that to argue that the government is free to infringe upon the rights of noncitizens.
The Constitution makes it clear that these rights are universal by saying that the government may not make laws that infringe upon them. They aren't granting rights, they are declaring which rights they must abide by. And with that, the use of "the people" in the part about free assembly should rely more on the context there then the preamble, where it clearly means "the people assembling" not "the citizens assembling."
Further on your "persons" point, the relevant Fourth Amendment makes it clear the terms are interchangeable.
>The right of the people to be secure in their persons...
No, it talks about "the people." As in the preamble: "We the People of the United States."
> However, there is a long history of interpreting 'people' to mean specific groups - from only white people to only citizens.
Playing with the interpretation of "people" has never been a mechanism for excluding people from constitutional protection. For example, the 3/5ths clause states as follows:
> Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons
It refers to enslaved people as "persons." The Fugitive Slave clause likewise refers to a "person held to service or labour."