Update run_demo.sh

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: spiralgang

run_demo.sh

@@ -13,8 +13,12 @@ fi
 
 # 2. Modify the manifest for the demo
 echo "--- Modifying SCM for Demo ---"
-# Using sed to change the log_file path in the manifest
-sed -i 's/thought_log.txt/demo_thought_log.txt/' polyglot_state.yaml
+# Using yq to change the log_file path in the manifest
+if ! command -v yq >/dev/null 2>&1; then
+    echo "yq is required but not installed. Please install yq (https://mikefarah.gitbook.io/yq/) and rerun this script."
+    exit 1
+fi
+yq -i '.log_file = "demo_thought_log.txt"' polyglot_state.yaml
 
 # 3. Launch the agent with the modified SCM
 echo "--- Launching Agent ---"