GHSA-xphw-cqx3-667j: thin-vec: Use-After-Free and Double Free in IntoIter::drop When Element Drop Panics

A Double Free / Use-After-Free (UAF) vulnerability has been identified in the IntoIter::drop and ThinVec::clear implementations of the thin_vec crate. Both vulnerabilities share the same root cause and can trigger memory corruption using only safe Rust code — no unsafe blocks required. Undefined Behavior has been confirmed via Miri and AddressSanitizer (ASAN).