docs(prover): remove stale write-bypass mention from module doc comment

The module doc incorrectly listed write-bypass violation detection as a
prover capability. The prover only checks reachability queries; write-bypass
detection was never implemented.

Signed-off-by: Evie Howard <evhoward@redhat.com>

Author: eviehoward

crates/openshell-prover/src/lib.rs

@@ -5,7 +5,7 @@
 //!
 //! Encodes sandbox policies, binary capabilities, and credential scopes as Z3
 //! SMT constraints, then checks reachability queries to detect data exfiltration
-//! paths and write-bypass violations.
+//! paths.
 
 pub mod accepted_risks;
 pub mod containment;