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.

conf.d/starship.fish

@@ -5,6 +5,9 @@
 # Without starship, fish's built-in prompt already emits OSC 133;A
 # on the prompt line itself, so no wrapper is needed.
 
+# Replacing the prompt is opinionated (C3 overrides)
+__fish_config_op_enabled __fish_config_op_overrides; or return
+
 type -q starship; or return
 
 function fish_prompt