tests: close remaining contract gaps (action-dispatch, org-headline-add/find-by-id, tangle-sync, create-note, messaging-link/unlink)

org/programming-literate.org

@@ -132,4 +132,10 @@ contents of the Lisp file. Returns T if they match, or an error message."
 (test test-block-balance-check-missing-close
   "Contract 2: unbalanced parens return non-T."
   (is (not (eq t (literate-block-balance-check "org/nonexistent-file-xyz.org")))))
+
+(test test-tangle-sync-check
+  "Contract 3: literate-tangle-sync-check verifies org matches tangled lisp."
+  (let ((result (literate-tangle-sync-check "org/core-loop.org" "lisp/core-loop.lisp")))
+    (is (or (eq t result) (stringp result))
+        "Should return T or a mismatch description")))
 #+end_src