feat: add system disclosure policy gate

direct-chat-service.mjs

@@ -155,7 +155,7 @@ function buildModelMessages({ previousMessages, userMessage, memories, routingMe
   ];
 }
 
-function buildAssistantMessage(reply, { requestId, now }) {
+function buildAssistantMessage(reply, { requestId, now, metadata = {} }) {
   return {
     id: `direct-assistant-${requestId || crypto.randomUUID()}`,
     role: 'assistant',
@@ -165,6 +165,7 @@ function buildAssistantMessage(reply, { requestId, now }) {
       userVisible: true,
       source: 'portal-direct-chat',
       chatRequestId: requestId || undefined,
+      ...metadata,
     },
   };
 }
@@ -440,10 +441,60 @@ export function createDirectChatService({
     };
   }
 
+  async function respondDeterministically({
+    userId,
+    sessionId = null,
+    requestId,
+    userMessage,
+    reply,
+    metadata = {},
+    onSessionReady = null,
+  } = {}) {
+    const activeSessionId = sessionId || createDirectSessionId();
+    const snapshot = await sessionSnapshotService.get(activeSessionId).catch(() => null);
+    const previousMessages = Array.isArray(snapshot?.messages) ? snapshot.messages : [];
+    const now = new Date().toISOString();
+    if (!sessionId) {
+      await sessionStore.registerAgentSession(userId, activeSessionId, 'h5-direct');
+    }
+    if (typeof onSessionReady === 'function') {
+      await onSessionReady(activeSessionId);
+    }
+    const pendingMessages = [...previousMessages, userMessage];
+    const assistantMessage = buildAssistantMessage(String(reply ?? ''), {
+      requestId,
+      now,
+      metadata,
+    });
+    const messages = [...pendingMessages, assistantMessage];
+    const session = {
+      id: activeSessionId,
+      name: snapshot?.session?.name ?? 'New Chat',
+      working_dir: snapshot?.session?.working_dir ?? '',
+      message_count: messages.length,
+      created_at: snapshot?.session?.created_at ?? now,
+      updated_at: now,
+      user_set_name: snapshot?.session?.user_set_name ?? false,
+      recipe: snapshot?.session?.recipe ?? null,
+      conversation: messages,
+    };
+    await sessionSnapshotService.save(activeSessionId, userId, session, messages);
+    return {
+      ok: true,
+      sessionId: activeSessionId,
+      messages,
+      session,
+      assistantMessage,
+      billing: null,
+      deterministic: true,
+    };
+  }
+
   return {
     getStatus,
     canHandle,
     explainCanHandle,
+    respondDeterministically,
     run,
   };
 }