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

org/gateway-tui-main.org

@@ -213,7 +213,7 @@ Event handlers + daemon I/O + main loop.
 (fiveam:in-suite tui-suite)
 
 (fiveam:test test-tui-connection-drop
-  "Tier 2 Chaos: Verify that handle-return degrades gracefully when the daemon connection is lost."
+  "Contract 4: handle-return enqueues error on connection loss."
   (let ((passepartout.gateway-tui::*incoming-msgs* nil)
         (passepartout.gateway-tui::*input-buffer* (make-array 5 :element-type 'character :initial-contents "hello" :fill-pointer 5 :adjustable t))
         (mock-stream (make-string-output-stream)))