Add codex_tmux_resume helper

dotfiles/lib/functions/codex_tmux

@@ -3,7 +3,6 @@
 function codex_tmux {
     base=$(basename "$PWD")
     name="$base"
-
     if tmux has-session -t "$name" 2>/dev/null; then
         i=2
         while tmux has-session -t "${name}-${i}" 2>/dev/null; do

dotfiles/lib/functions/codex_tmux_resume

@@ -0,0 +1,32 @@
+#!/usr/bin/env sh
+
+function codex_tmux_resume {
+    base=$(basename "$PWD")
+    target=$(tmux list-sessions -F '#S' 2>/dev/null | awk -v base="$base" '
+        $0 == base { print; found=1; exit }
+        {
+            prefix = base "-"
+            if (substr($0, 1, length(prefix)) == prefix) {
+                rest = substr($0, length(prefix) + 1)
+                if (rest ~ /^[0-9]+$/) {
+                    n = rest + 0
+                    if (n > max) { max = n; best = $0 }
+                }
+            }
+        }
+        END { if (found != 1 && best != "") print best }
+    ')
+
+    if [ -n "$target" ]; then
+        if [ -n "$TMUX" ]; then
+            tmux switch-client -t "$target"
+        else
+            tmux attach-session -t "$target"
+        fi
+        return 0
+    fi
+
+    codex_tmux "$@"
+}
+
+codex_tmux_resume "$@"