fix(logging): suppress Kitty watcher capture when C5 logging is disabled

When smart_exit skips fish-side capture due to the C5 guard, it now sets
logged_by_shell=true on the Kitty window before calling builtin exit. This
prevents watcher.py's on_close handler from capturing the scrollback even
if the sentinel file is absent, providing a second layer of protection.

Also restructures the capture block to be flat (no wrapper if-true) after
the early-exit guard.

functions/smart_exit.fish

@@ -48,8 +48,16 @@ function smart_exit --description 'Capture colorized scrollback before exiting,
         return 0
     end
 
-    # C5 — Logging & Capture: skip all capture when logging is disabled
-    if __fish_config_op_enabled __fish_config_op_logging
+    # C5 — Logging & Capture: skip all capture when logging is disabled.
+    # When disabled, tell Kitty the window is handled so its watcher doesn't
+    # capture either — belt-and-suspenders alongside the sentinel file.
+    if not __fish_config_op_enabled __fish_config_op_logging
+        if test -n "$KITTY_WINDOW_ID"
+            kitty @ set-user-vars "logged_by_shell=true" 2>/dev/null
+        end
+        builtin exit
+    end
+
     set -l snapshot_dir (set -q SCROLLBACK_HISTORY_DIR; and echo $SCROLLBACK_HISTORY_DIR; or echo "$HOME/.terminal_history")
     set -l max_files (set -q SCROLLBACK_HISTORY_MAX_FILES; and echo $SCROLLBACK_HISTORY_MAX_FILES; or echo 100)
 
@@ -94,7 +102,6 @@ function smart_exit --description 'Capture colorized scrollback before exiting,
         echo -e "$c_warn""➔""$c_reset Exiting discreetly; $c_bold""no history logs saved.""$c_reset"
         sleep 0.4
     end
-    end
 
     # Call the true system exit directly
     builtin exit