feat(opencode): add completion and alias plugin for opencode

Signed-off-by: Pranav Avva <pranav.avva@gmail.com>

plugins/opencode/opencode.plugin.zsh

@@ -0,0 +1,28 @@
+if ! (( $+commands[opencode] )); then
+  print "zsh opencode plugin: opencode not found. Please install opencode before using this plugin." >&2
+  return 1
+fi
+
+# See `opencode completion`
+_opencode_yargs_completions() {
+  local reply
+  local si=$IFS
+  IFS=$'
+' reply=($(COMP_CWORD="$((CURRENT-1))" COMP_LINE="$BUFFER" COMP_POINT="$CURSOR" opencode --get-yargs-completions "${words[@]}"))
+  IFS=$si
+  if [[ ${#reply} -gt 0 ]]; then
+    _describe 'values' reply
+  else
+    _default
+  fi
+}
+
+if [[ "'${zsh_eval_context[-1]}" == "loadautofunc" ]]; then
+  _opencode_yargs_completions "$@"
+else
+  compdef _opencode_yargs_completions opencode
+fi
+
+# Aliases
+alias oc="opencode"
+alias ocr="opencode run"