Implement authorized landmark roaming (#130)

crates/metacrate-grid-agent/tests/dependency_policy.rs

@@ -48,10 +48,10 @@ fn package_has_only_reviewed_rust_dependencies_and_no_build_script() {
 #[test]
 fn runtime_source_has_no_subprocess_or_native_abi_escape_hatch() {
     let source = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("src");
-    let mut files = Vec::with_capacity(20);
+    let mut files = Vec::with_capacity(32);
     collect_rust_files(&source, &mut files);
     assert!(
-        files.len() <= 30,
+        files.len() <= 32,
         "source-file count needs a reviewed bound update"
     );
     for path in files {