fix: ensure userVisible metadata on Goosed session replies

Goosed rejects /sessions/:id/reply when user_message.metadata lacks
userVisible. Normalize metadata before submit and during agent orchestration
so page-generation runs no longer fail before streaming starts.

Co-authored-by: Cursor <cursoragent@cursor.com>

chat-intent-router.mjs

@@ -406,6 +406,8 @@ export function applyAgentOrchestrationToUserMessage(userMessage, classification
     displayText: displayText || undefined,
     chatIntentRoute: CHAT_INTENT_ROUTE.AGENT,
     chatIntentSource: classification?.source ?? null,
+    userVisible: userMessage?.metadata?.userVisible ?? true,
+    agentVisible: userMessage?.metadata?.agentVisible ?? true,
   };
   return {
     ...userMessage,