Fix critical bug: incorrect return code check in exit logic

The issue was in line 378: if [[ $? -eq 0 ]]
- $? was checking the return code of 'local exit_reason=$(...)'
- This command always succeeds, so $? was always 0
- This caused Ralph to always exit immediately after loop #1

Fixed by:
- Calling should_exit_gracefully directly in the if condition
- Only calling it again to get exit reason if it returns 0 (exit needed)
- This properly checks the function's actual return code

ralph_loop.sh

@@ -374,8 +374,8 @@ main() {
         fi
         
         # Check for graceful exit conditions
-        local exit_reason=$(should_exit_gracefully)
-        if [[ $? -eq 0 ]]; then
+        if should_exit_gracefully; then
+            local exit_reason=$(should_exit_gracefully)
             log_status "SUCCESS" "🏁 Graceful exit triggered: $exit_reason"
             update_status "$loop_count" "$(cat "$CALL_COUNT_FILE")" "graceful_exit" "completed" "$exit_reason"