fix: CLI test, TUI integration harness — all non-blockers resolved

- gateway-cli: add load-time sanity check, fix FiveAM prefix for
  jailed-package compatibility
- TUI integration: switch all tests from file-grep to tmux capture-pane
  (agent-responds, cascade-failure, eval-command, connection-drop).
  Fixes file-buffering false negatives. Increase eval sleep to 3s.
- Cherry-pick: system-integration-tests.org org source updated

lisp/gateway-cli.lisp

@@ -15,17 +15,21 @@
   (ql:quickload :fiveam :silent t))
 
 (defpackage :passepartout-gateway-cli-tests
-  (:use :cl :fiveam :passepartout)
+  (:use :cl :passepartout)
   (:export #:cli-suite))
 
 (in-package :passepartout-gateway-cli-tests)
 
-(def-suite cli-suite :description "Verification of the CLI Gateway")
-(in-suite cli-suite)
+(fiveam:def-suite cli-suite :description "Verification of the CLI Gateway")
+(fiveam:in-suite cli-suite)
 
-(test test-gateway-cli-input-format
+(fiveam:test test-gateway-cli-input-format
   "Contract 1: gateway-cli-input injects a properly formed signal without error."
   (handler-case
-      (gateway-cli-input "hello")
+      (progn (gateway-cli-input "hello") (fiveam:is t))
     (error (c)
-      (fail "gateway-cli-input crashed: ~a" c))))
+      (fiveam:is nil "gateway-cli-input crashed: ~a" c))))
+
+(handler-case
+    (progn (gateway-cli-input "test-load") (log-message "CLI: Load-time test OK"))
+  (error (c) (log-message "CLI: Load-time test FAILED: ~a" c)))