fix: use temp file for message to avoid shell parsing issues

The message passed to opencode run contains newlines and special
characters (parentheses, etc.) which break shell parsing when passed
directly in double quotes.

Fix by writing message to temp file and using '@msg_file' syntax
to pass to opencode run. This handles any characters in the message.

skills/kugetsu/scripts/kugetsu-session.sh

@@ -225,7 +225,10 @@ cmd_delegate() {
         exit 1
     fi
     
-    nohup sh -c "GITEA_TOKEN='${GITEA_TOKEN:-}' opencode run '$message' --session '$new_session'" >> "$log_file" 2>&1 &
+    local msg_file="$LOGS_DIR/msg-$new_session.txt"
+    printf '%s' "$message" > "$msg_file"
+    nohup sh -c "GITEA_TOKEN='${GITEA_TOKEN:-}' opencode run '@$msg_file' --session '$new_session'" >> "$log_file" 2>&1 &
+    rm -f "$msg_file"
     echo "Delegated to new session (logged to $(basename "$log_file"))"
 }
 
@@ -373,7 +376,10 @@ cmd_start() {
     load_agent_env "dev"
     
     cd "$worktree_path"
-    nohup sh -c "GITEA_TOKEN='${GITEA_TOKEN:-}' opencode run '$dev_message' --session '$new_session_id'" >> "$LOGS_DIR/dev-$new_session_id.log" 2>&1 &
+    local msg_file="$LOGS_DIR/msg-$new_session_id.txt"
+    printf '%s' "$dev_message" > "$msg_file"
+    nohup sh -c "GITEA_TOKEN='${GITEA_TOKEN:-}' opencode run '@$msg_file' --session '$new_session_id'" >> "$LOGS_DIR/dev-$new_session_id.log" 2>&1 &
+    rm -f "$msg_file"
     
     echo "Session started for '$issue_ref': $new_session_id"
     echo "Worktree: $worktree_path"
@@ -436,7 +442,10 @@ cmd_continue() {
     fi
     
     cd "$worktree_path"
-    nohup sh -c "GITEA_TOKEN='${GITEA_TOKEN:-}' opencode run '$message' --session '$opencode_session_id'" >> "$LOGS_DIR/dev-$opencode_session_id.log" 2>&1 &
+    local msg_file="$LOGS_DIR/msg-$opencode_session_id.txt"
+    printf '%s' "$message" > "$msg_file"
+    nohup sh -c "GITEA_TOKEN='${GITEA_TOKEN:-}' opencode run '@$msg_file' --session '$opencode_session_id'" >> "$LOGS_DIR/dev-$opencode_session_id.log" 2>&1 &
+    rm -f "$msg_file"
 }
 
 cmd_list() {