feat(engine): rename facade to oakengine, build liboakengine.dylib

- src/facade/rust -> src/engine/rust; package oakfacade -> oakengine
- crate-type += cdylib; module crates are real deps; linkage anchors
  force-link module C ABIs into the dylib
- build.rs: -undefined dynamic_lookup for host-provided oakcore_*/fb_*
- nm: 749 oakengine_* + 687 module oak*_* exports; undefined set is
  only the intended host-provided symbols
- worker/cli updated to the new path/name; undo test race fix

cli/rust/tests/cli.rs

@@ -71,7 +71,9 @@ fn info_on_a_fixture_reports_not_yet_available() {
     let (code, _stdout, stderr) = run(&["info", "tests/project_with_footage.ove"]);
     assert_eq!(code, 1);
     assert!(stderr.contains("error: info: not yet available"), "stderr: {stderr}");
-    assert!(stderr.contains("oakfacade"));
+    // The crate was renamed oakfacade -> oakengine; the deferral reason
+    // names the current crate.
+    assert!(stderr.contains("oakengine"));
 }
 
 #[test]