"You have no natural rights. There's simply no such thing. Rights are a human construct."
Not familiar with Locke I guess.
Anyway, the best way to look at natural rights is to consider those things that an individual would have if he were the last individual on earth. He would have the right to all he created or foraged. he would have the right to breate air. He would have the right to drink water.
Furthermore, your argument suggests that things like breathing and eating are rights that are afforded by...government I guess? I'm not really sure. It's a pretty far-out-there position to state that every bit of my being is allowed to function at the pleasure of government.
"And even if you did, those rights are meaningless without some sort of authority to enforce those rights."
I am the authority to protect and enforce those rights. Or abandon them if and when I choose.
"Certain things stolen are irrecoverable. How do you steal back a rape? Your ideas are nonsense."
Is rape theft? What about a kick to the nuts. What about a kiss?
These ideas are nonsense, but they're yours. Not mine.
"Why didn't Anne Frank exercise her "natural right" to stay alive?"
She was exercising her rights. They were violated by the National Socialists.
"Because she didn't have an enforcement mechanism to make her right manifest."
Your position would seem to be that her rights were not violated in the first place, as all rights come from government (or other man-made institution). And as such, she should have never had any expectation for any other form of treatment from the National Socialists.
My position would be that she did have natural rights, they were violated, and this violation led to the Socialists getting their grills kicked in. By both governmental agencies such as the US Army, and non-governmental partisan groups that were defending their natural rights.