v0.4.0: TUI differentiator visualization — gate trace, rule counter, focus map

Gate trace: cognitive-verify accumulates (:gate name :result status) for
each deterministic gate. Trace prepended to action plist via list*.
TUI on-daemon-msg extracts :gate-trace and stores on message object.
add-msg accepts &key gate-trace for future rendering (collapsible Tab).

Rule counter: TUI actuator enriches response payload with :rule-count
=(hash-table-count *hitl-pending*). TUI status bar shows 'Rules:N'.

Focus map: TUI actuator adds :foveal-id from signal context. TUI stores
in state and renders second status line '[Focus: id]'.

Status bar: now two lines — line 1 (connection, mode, msgs, scroll,
rules, thinking spinner), line 2 (focus map, timestamp).

Test: 112/0 across 14 suites (reason 15/0 including gate-trace assertions)

lisp/gateway-tui-model.lisp

@@ -59,8 +59,8 @@
         (setf (st :input-buffer) (reverse (coerce new 'list)))
         (setf (st :cursor-pos) (1- pos))))))
 
-(defun add-msg (role content)
-  (vector-push-extend (list :role role :content content :time (now)) (st :messages))
+(defun add-msg (role content &key gate-trace)
+  (vector-push-extend (list :role role :content content :time (now) :gate-trace gate-trace) (st :messages))
   (setf (st :dirty) (list t t nil)))
 
 (defun queue-event (ev)