fix(tmux): use heredoc for config to handle special characters

The previous implementation using inline variable assignment and printf
caused issues with custom tmux configs containing special characters:

1. `TMUX_CONFIG="${TMUX_CONFIG}"` - Terraform's templatefile substitutes
   the multi-line config inline, causing bash to interpret tmux commands
   (like `set -g`, `bind C-s`) as shell commands.

2. `printf "$TMUX_CONFIG"` - The `%` character in tmux's default
   horizontal split keybind (`bind %`) is interpreted as a printf format
   specifier, corrupting the output.

Changes:
- Use heredoc with `read -r -d ''` for safe variable assignment
- Use `cat <<<` instead of `printf` for output
- Add `|| true` to handle read's non-zero exit on EOF

registry/anomaly/modules/tmux/scripts/run.sh

@@ -4,7 +4,9 @@ BOLD='\033[0;1m'
 
 # Convert templated variables to shell variables
 SAVE_INTERVAL="${SAVE_INTERVAL}"
-TMUX_CONFIG="${TMUX_CONFIG}"
+read -r -d '' TMUX_CONFIG << 'TMUX_EOF' || true
+${TMUX_CONFIG}
+TMUX_EOF
 
 # Function to install tmux
 install_tmux() {
@@ -73,7 +75,7 @@ setup_tmux_config() {
   mkdir -p "$config_dir"
 
   if [ -n "$TMUX_CONFIG" ]; then
-    printf "$TMUX_CONFIG" > "$config_file"
+    cat <<< "$TMUX_CONFIG" > "$config_file"
     printf "$${BOLD}Custom tmux configuration applied at {$config_file} \n\n"
   else
     cat > "$config_file" << EOF