feat(logging): add C5 --on-variable event handlers for real-time sync

functions/__fish_config_logging_changed.fish

@@ -0,0 +1,21 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# SYNOPSIS
+#   __fish_config_logging_changed
+#
+# DESCRIPTION
+#   Event handler that fires in every running shell when
+#   __fish_config_op_logging is set or erased. Delegates to
+#   __fish_config_sync_logging to update the Kitty sentinel file and
+#   paru/yay wrappers immediately without requiring a shell restart.
+#
+# RETURNS
+#   0  Always
+#
+# EXAMPLE
+#   set -U __fish_config_op_logging 0  # triggers this automatically
+function __fish_config_logging_changed --on-variable __fish_config_op_logging \
+    --description 'C5 event handler: sync logging state when __fish_config_op_logging changes'
+    __fish_config_sync_logging
+end

functions/__fish_config_opinionated_changed.fish

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+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# SYNOPSIS
+#   __fish_config_opinionated_changed
+#
+# DESCRIPTION
+#   Event handler that fires in every running shell when
+#   __fish_config_opinionated (the master opinionated switch) is set or
+#   erased. Delegates to __fish_config_sync_logging to keep C5 logging
+#   state in sync. Logging is the only category with external on-disk
+#   state (sentinel file, wrapper scripts) that requires real-time
+#   synchronisation when the master variable changes; C1-C4 guards
+#   evaluate at call-time and need no event handler.
+#
+# RETURNS
+#   0  Always
+#
+# EXAMPLE
+#   set -U __fish_config_opinionated 0  # triggers this automatically
+function __fish_config_opinionated_changed --on-variable __fish_config_opinionated \
+    --description 'C5 event handler: sync logging state when master opinionated switch changes'
+    __fish_config_sync_logging
+end