The py/cs LSP benchmark tests have time-budget asserts (<150ms / <200ms) that ASan+UBSan blow on CI (750-900ms on arm64), so they bailed before cbm_free_result and LeakSanitizer flagged the leaked arena/parser. Gate them behind CBM_SKIP_PERF (set by the dry-run) like the incremental perf tests, so they run only when perf is enabled.
Fix Windows (msys2-clang) compile errors in test code by using the existing compat shims: setenv/unsetenv -> cbm_setenv/cbm_unsetenv (test_store_pragmas, test_ts_lsp), strndup -> cbm_strndup and 2-arg mkdir -> cbm_mkdir (test_path_alias), and guard the utimensat mtime-bump in test_pipeline behind #ifndef _WIN32.