feat!: Add support for "iw" command

- CLI completion for iw (Linux wireless configuration utility).
- Directly parses "iw help" output to discover commands and caches the result.
- $service is used as the iw binary name. This allows this completion to work
  for differently-named iw binaries: compdef _iw my-iw-binary

plugins/iw/iw.plugin.zsh

@@ -0,0 +1,17 @@
+# iw Oh-My-ZSH plugin
+# Provides tab completion for iw (Linux wireless configuration utility).
+
+if (( ! $+commands[iw] )); then
+  return
+fi
+
+# Remove the cached iw completion data (useful after upgrading iw).
+iw-clear-cache() {
+  local cache_file="${ZSH_CACHE_DIR:-${HOME}/.cache}/_iw_cache"
+  if [[ -f "$cache_file" ]]; then
+    rm -f "$cache_file"
+    print "iw completion cache cleared."
+  else
+    print "No iw completion cache found."
+  fi
+}