feat(guards): add opinionated component guards to config.fish and conf.d

Adds __fish_config_op_enabled helper (master __fish_config_opinionated
evaluated first via __fish_variable_check, then the category variable)
and gates C1-C4 components: CachyOS surgical override, PAGER/MANPAGER,
CDPATH, Vi mode, exit override, bang-bang bindings, history/cp/mv/wget/
grep aliases, cd->z alias, Fisher bootstrap and theme apply, paru/yay
wrapper generation, WakaTime hook, custom key chords, puffer, autopair,
starship prompt, Catppuccin colors, FZF_DEFAULT_OPTS, done notifications,
and Kitty/WezTerm window-management abbreviations.

functions/__fish_config_op_enabled.fish

@@ -0,0 +1,46 @@
+# Copyright (C) 2026 Rootiest
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+# SYNOPSIS
+#   __fish_config_op_enabled <category_variable>
+#
+# DESCRIPTION
+#   Guard predicate for opinionated components (AGENTS.md Task #3). The master
+#   switch __fish_config_opinionated is always evaluated first via
+#   __fish_variable_check: a falsy master value (0/false/no/off/n) disables
+#   every category at once, regardless of the category variable's own value.
+#   Otherwise the supplied category variable is evaluated the same way.
+#   Unset or empty variables (status 2) and unrecognized values (status 3)
+#   leave the component enabled — opinionated components are active by
+#   default and these variables are pure opt-out knobs.
+#
+# ARGUMENTS
+#   category_variable  Name (without $) of the category opt-out variable:
+#                      __fish_config_op_aliases, __fish_config_op_autoexec,
+#                      __fish_config_op_overrides, or
+#                      __fish_config_op_integrations
+#
+# RETURNS
+#   0  Component enabled (variables truthy, unset, or unrecognized)
+#   1  Component disabled (master or category variable is falsy)
+#
+# EXAMPLE
+#   if __fish_config_op_enabled __fish_config_op_aliases
+#       alias grep='grep --color=auto'
+#   end
+function __fish_config_op_enabled --description 'Check whether an opinionated component category is enabled'
+    # Master switch first: falsy disables all categories unconditionally.
+    __fish_variable_check __fish_config_opinionated
+    if test $status -eq 1
+        return 1
+    end
+
+    # Category variable: only an explicit falsy value disables the category.
+    # Truthy (0), unset/empty (2), and garbage (3) all keep it enabled.
+    __fish_variable_check $argv[1]
+    if test $status -eq 1
+        return 1
+    end
+
+    return 0
+end