quit when input ends at the guess prompt

At end of input (Ctrl-D, or stdin closed) read returns straight away
with an empty guess, so the "Must be 5 letters" loop spun forever at
full CPU. If the game's parent process was killed first, the subshell
was left orphaned and spinning.

Exit retrieve_guess when read hits EOF, pass that back through the
retry prompts with a single recursive call, and quit from main.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

wordle

@@ -58,7 +58,7 @@ function main() {
   for (( ROW; ROW<HEIGHT; ROW++ )); do
     declare GUESS
     [[ "${KEYBOARD}" == 1 ]] && render_keyboard
-    GUESS=$(retrieve_guess)
+    GUESS=$(retrieve_guess) || { echo -en "${NEWLINE}"; exit 0; }
     check_guess "${GUESS}" "${ROW}" ; WIN=$?
 
     # Save before the reveal so quitting or disconnecting can't undo a guess
@@ -243,25 +243,31 @@ function render_board() {
   [[ "${BORDER}" == 1 ]] && echo -e "└─────────────────┘"
 }
 
+# Exits non-zero at end of input (Ctrl-D) so the caller can quit
 function retrieve_guess() {
   if  [[ -n $1 ]]; then
-    read -r -p "${CLEAR_UP1}$1: " GUESS
+    read -r -p "${CLEAR_UP1}$1: " GUESS || exit 1
   else
-    read -r -p "${CLEAR_2END}Enter Guess: " GUESS
+    read -r -p "${CLEAR_2END}Enter Guess: " GUESS || exit 1
   fi
 
   while [[ ${#GUESS} -ne 5 ]] || [[ ! "${GUESS,,}" =~ ^[a-z]{5}$ ]]; do
-    read -r -p "${CLEAR_UP1}Must be 5 letters: " GUESS
-  done 
+    read -r -p "${CLEAR_UP1}Must be 5 letters: " GUESS || exit 1
+  done
   declare valid_guess
   validate_guess "${GUESS}" ; valid_guess=$?
 
-  [[ ${valid_guess} == 1 ]] && GUESS=$(retrieve_guess "Not A Valid Word")
-  [[ ${valid_guess} == 2 ]] && GUESS=$(retrieve_guess "Not A Valid Guess")
-  [[ ${valid_guess} == 3 ]] && GUESS=$(retrieve_guess "GREEN Issue")
-  [[ ${valid_guess} == 4 ]] && GUESS=$(retrieve_guess "YELLOW Issue")
-  [[ ${valid_guess} == 5 ]] && GUESS=$(retrieve_guess "POOL Issue")
-  [[ ${valid_guess} == 6 ]] && GUESS=$(retrieve_guess "NEW Issue")
+  declare message
+  [[ ${valid_guess} == 1 ]] && message="Not A Valid Word"
+  [[ ${valid_guess} == 2 ]] && message="Not A Valid Guess"
+  [[ ${valid_guess} == 3 ]] && message="GREEN Issue"
+  [[ ${valid_guess} == 4 ]] && message="YELLOW Issue"
+  [[ ${valid_guess} == 5 ]] && message="POOL Issue"
+  [[ ${valid_guess} == 6 ]] && message="NEW Issue"
+
+  if [[ -n "${message}" ]]; then
+    GUESS=$(retrieve_guess "${message}") || exit 1
+  fi
 
   echo -n "${GUESS^^}"
 }