feat(guards): add in-function opinionated guards and CachyOS cleanup

C1 shadows (rm, cat, ls, less, du, bash, top, ping, ssh, rg, mkdir,
help) fall back to the bare command when __fish_config_op_aliases is
falsy; rm falls back to exact 'command rm' with no wrapper. C2 gates
the auto-venv PWD hook. C3 gates smart_exit (composing with Task #4
logging), fish_right_prompt, and all six expand_bang_*/expand_typo_sub
functions atomically with the bang-bang system. C4 integration commands
(spwin, tab, split, hist, logs, upgrade) refuse with a colored stderr
error when disabled. config.fish now also strips the CachyOS distro
config's own bang-bang bindings, history override, and alias opinions
per category, restoring fish stock functions where they exist.

functions/fish_right_prompt.fish

@@ -11,6 +11,9 @@
 # EXAMPLE
 #   # Rendered automatically by Fish shell; not called directly.
 function fish_right_prompt --description 'Execute fish_right_prompt'
+    # Opinionated guard (C3): no right prompt when overrides are disabled.
+    __fish_config_op_enabled __fish_config_op_overrides; or return
+
     # 1. Docker Context in Blue
     set -l docker_ctx (docker context show 2>/dev/null)
     if test -n "$docker_ctx"; and test "$docker_ctx" != default