Claude review: rust: types: add `ForLt` trait for higher-ranked lifetime support

[Claude Code Review Bot <claude-review@example.com>]

Patch Review

Well-designed `ForLt` infrastructure. The covariance proof mechanism via `Prover` is thorough, handling references, arrays, tuples, and const pointers syntactically while deferring to the compiler for complex cases.

The `cast_ref` implementation using `transmute` is sound given the covariance guarantee:
```rust
fn cast_ref<'r, 'short: 'r, 'long: 'short>(long: &'r Self::Of<'long>) -> &'r Self::Of<'short> {
    unsafe { core::mem::transmute(long) }
}
```

The wellformedness check via `ProveWf` structs to work around rust-lang/rust#152489 is a nice defensive measure. The "Apache-2.0 OR MIT" license for anticipated pin-init crate reuse is reasonable.

Minor: the doc comment has a typo "shorterned" (line 551 of the mbox) -- should be "shortened".

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Generated by Claude Code Patch Reviewer