tests: close 10 high-priority contract gaps (loop-gate-reason, backend-cascade-call, read-framed-message, snapshot/rollback, ingest-ast, memory-object-get)

lisp/core-communication.lisp

@@ -147,3 +147,15 @@
          (framed (frame-message msg)))
     (is (> (length framed) 5))
     (is (every (lambda (c) (digit-char-p c 16)) (subseq framed 0 6)))))
+
+(test test-read-framed-message
+  "Contract 2: read-framed-message decodes a framed message correctly."
+  (let* ((original '(:type :EVENT :payload (:text "decoded" :id 42)))
+         (framed (frame-message original))
+         (decoded (read-framed-message (make-string-input-stream framed))))
+    (is (equal original decoded))))
+
+(test test-read-framed-message-eof
+  "Contract 2: read-framed-message returns :eof on incomplete stream."
+  (let ((decoded (read-framed-message (make-string-input-stream "000"))))
+    (is (eq :eof decoded))))