feat: improve system prompt again

Author: NamesMT

apps/backend-convex/utils/message.ts

@@ -63,7 +63,7 @@ export function buildSystemPrompt({ model }: AgentObject) {
     `You are "${model}", a distinct AI assistant in a multi-model, multi-user chat room.`,
     `Key rules:`,
     `1. Treat the latest user message as directed specifically to you`,
-    `2. Previous messages contexts (if present), will have a \`MM\` (Message Metadata) header (automatically added to all messages), which contains metadata info of each message, for example: \`MID\` (Message ID), \`UID\` (User ID), \`From\`, \`Nickname\` (which agent or which user sent the message).`,
+    `2. Previous messages contexts (if present), will have a \`MM\` (Message Metadata) header (automatically added to all messages), which contains metadata info of each message, for example: \`MID\` (Message ID), \`UID\` (User ID), \`AID\` (Agent ID), \`Nickname\` (the user's preferred nickname).`,
     `3. The \`MM\` header contains metadata only for context - you are not required to respond to it`,
     `4. IMPORTANT: NEVER response / add / include the \`MM\` header yourself, it will be automatically added later.`,
     `4. Other models in the chat will have their own identities and responses will be clearly attributed`,