feat(zellij): add session functions, convenience commands, and smart completions

- Use functions for attach/delete/kill to enable session-aware completions
- Add zr, zrf, ze convenience functions with conflict detection
- Improve z prefix collision check (aliases, functions, commands)
- Cache completions synchronously on first load, background on updates
- Update README to document new functions and completion behavior

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/zellij/zellij.plugin.zsh

@@ -2,34 +2,82 @@ if (( ! $+commands[zellij] )); then
   return
 fi
 
-# Dynamic prefix: use "zj" by default, use "z" if ZSH_ZELLIJ_PREFIX_Z is set and "z" is available
-if [[ -n "$ZSH_ZELLIJ_PREFIX_Z" ]] && (( ! $+aliases[z] )); then
-  _zellij_prefix="z"
+if [[ -n ${ZSH_ZELLIJ_PREFIX_Z:-} ]]; then
+  _zellij_prefix=z
 else
-  _zellij_prefix="zj"
+  _zellij_prefix=zj
 fi
 
-# Aliases
-alias ${_zellij_prefix}='zellij'
-alias ${_zellij_prefix}a='zellij attach'
-alias ${_zellij_prefix}d='zellij delete-session'
-alias ${_zellij_prefix}da='zellij delete-all-sessions'
-alias ${_zellij_prefix}k='zellij kill-session'
-alias ${_zellij_prefix}ka='zellij kill-all-sessions'
+
+if [[ -n ${ZSH_ZELLIJ_PREFIX_Z:-} ]] && (( ! $+aliases[z] && ! $+functions[z] && ! $+commands[z] )); then
+  alias z='zellij'
+else
+  alias zj='zellij'
+fi
+
+# alias ${_zellij_prefix}='zellij'
 alias ${_zellij_prefix}l='zellij list-sessions'
-alias ${_zellij_prefix}r='zellij run'
 alias ${_zellij_prefix}s='zellij -s'
+alias ${_zellij_prefix}da='zellij delete-all-sessions'
+alias ${_zellij_prefix}ka='zellij kill-all-sessions'
+[[ $_zellij_prefix != z ]] && alias ${_zellij_prefix}r='zellij run'
 
-unset _zellij_prefix
+eval "${_zellij_prefix}a() { command zellij attach \"\$@\"; }"
+eval "${_zellij_prefix}d() { command zellij delete-session \"\$@\"; }"
+eval "${_zellij_prefix}k() { command zellij kill-session \"\$@\"; }"
 
-# Completion caching (same pattern as gh plugin)
-# On first load, _zellij may not exist in fpath — autoload fails silently.
-# The background command generates the cache file for subsequent sessions.
-# Load order: plugin loads → compinit runs → next session picks up cached file.
-if [[ ! -f "$ZSH_CACHE_DIR/completions/_zellij" ]]; then
-  typeset -g -A _comps
-  autoload -Uz _zellij
-  _comps[zellij]=_zellij
+(( $+functions[zr] || $+aliases[zr] || $+commands[zr] )) || zr() { command zellij run -- "$@"; }
+(( $+functions[zrf] || $+aliases[zrf] || $+commands[zrf] )) || zrf() { command zellij run --floating -- "$@"; }
+(( $+functions[ze] || $+aliases[ze] || $+commands[ze] )) || ze() { command zellij edit "$@"; }
+
+_ZELLIJ_COMP_FILE="${ZSH_CACHE_DIR}/completions/_zellij"
+mkdir -p "${_ZELLIJ_COMP_FILE:h}"
+
+if [[ ! -s $_ZELLIJ_COMP_FILE ]]; then
+  command zellij setup --generate-completion zsh >| "$_ZELLIJ_COMP_FILE" 2>/dev/null
+elif [[ $commands[zellij] -nt $_ZELLIJ_COMP_FILE ]]; then
+  command zellij setup --generate-completion zsh >| "$_ZELLIJ_COMP_FILE" 2>/dev/null &!
 fi
 
-zellij setup --generate-completion zsh >| "$ZSH_CACHE_DIR/completions/_zellij" &|
+_omz_zellij_ls_raw() {
+  command zellij list-sessions --no-formatting 2>/dev/null || command zellij list-sessions 2>/dev/null
+}
+
+_omz_zellij_all_sessions() {
+  emulate -L zsh
+  local out
+  local -a sessions
+  out="$(_omz_zellij_ls_raw)"
+  sessions=("${(@f)$(printf '%s\n' "$out" | LC_ALL=C sed -nE 's/^([^[:space:]]+).*/\1/p')}")
+  (( ${#sessions[@]} )) && compadd -Q -a sessions
+}
+
+_omz_zellij_running_sessions() {
+  emulate -L zsh
+  local out
+  local -a sessions
+  out="$(_omz_zellij_ls_raw)"
+  sessions=("${(@f)$(printf '%s\n' "$out" | LC_ALL=C sed -nE '/EXITED/!s/^([^[:space:]]+).*/\1/p')}")
+  (( ${#sessions[@]} )) && compadd -Q -a sessions
+}
+
+_omz_zellij_exited_sessions() {
+  emulate -L zsh
+  local out
+  local -a sessions
+  out="$(_omz_zellij_ls_raw)"
+  sessions=("${(@f)$(printf '%s\n' "$out" | LC_ALL=C sed -nE '/EXITED/s/^([^[:space:]]+).*/\1/p')}")
+  (( ${#sessions[@]} )) && compadd -Q -a sessions
+}
+
+if (( $+functions[compdef] )); then
+  autoload -Uz _zellij
+  compdef _zellij zellij ${_zellij_prefix} ${_zellij_prefix}l ${_zellij_prefix}s
+  [[ $_zellij_prefix != z ]] && compdef _zellij ${_zellij_prefix}r
+  compdef _omz_zellij_all_sessions ${_zellij_prefix}a
+  compdef _omz_zellij_running_sessions ${_zellij_prefix}k
+  compdef _omz_zellij_exited_sessions ${_zellij_prefix}d
+fi
+
+unset _ZELLIJ_COMP_FILE
+unset _zellij_prefix