Add tmux session script for nix configuration workspace

- Create automated tmux session setup with 3 windows: nvim, ai, and bash
- Auto-start nvim in first window and claude in ai window with split panes
- Provides quick workspace initialization for nix config development

🤖 Generated with [Claude Code](https://claude.ai/code)

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

tmux.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+SESSION_NAME="nix"
+WORK_DIR="/Users/yanlin/.config/nix"
+
+if tmux has-session -t $SESSION_NAME 2>/dev/null; then
+    tmux attach-session -t $SESSION_NAME
+    exit 0
+fi
+
+tmux new-session -d -s $SESSION_NAME -c "$WORK_DIR"
+tmux rename-window -t $SESSION_NAME:1 "nvim"
+tmux send-keys -t $SESSION_NAME:1 "nvim" C-m
+tmux new-window -t $SESSION_NAME:2 -n "ai"
+tmux send-keys -t $SESSION_NAME:2 "claude -r" C-m
+tmux split-window -t $SESSION_NAME:2 -h
+tmux split-window -t $SESSION_NAME:2.2 -v
+tmux select-pane -t $SESSION_NAME:2.1
+tmux new-window -t $SESSION_NAME:3 -n "bash"
+
+tmux select-window -t $SESSION_NAME:1
+
+tmux attach-session -t $SESSION_NAME