feat(core): move context docs to user prompt (#10162)

Fix issue [BS-2522](https://linear.app/affine-design/issue/BS-2522).

### Why make this change?
If the user data contains illegal content, carrying the user data in the system prompt will run the risk of having the account banned.

### What Changed?
- Move the `Context Documents` to the user prompt.
- Add `withPrompt` in `QueryChatHistoriesInput` options.
- Get chat histories without prompt messages.
- Omit document context when saving messages to the `aiSessionMessage` db.

packages/backend/server/src/plugins/copilot/session.ts

@@ -2,6 +2,7 @@ import { randomUUID } from 'node:crypto';
 
 import { Injectable, Logger } from '@nestjs/common';
 import { AiPromptRole, Prisma, PrismaClient } from '@prisma/client';
+import { omit } from 'lodash-es';
 
 import {
   CopilotActionTaken,
@@ -255,7 +256,7 @@ export class ChatSessionService {
             data: state.messages.map(m => ({
               ...m,
               attachments: m.attachments || undefined,
-              params: m.params || undefined,
+              params: omit(m.params, ['docs']) || undefined,
               sessionId,
             })),
           });
@@ -415,8 +416,7 @@ export class ChatSessionService {
     userId: string,
     workspaceId?: string,
     docId?: string,
-    options?: ListHistoriesOptions,
-    withPrompt = false
+    options?: ListHistoriesOptions
   ): Promise<ChatHistory[]> {
     const extraCondition = [];
 
@@ -505,7 +505,7 @@ export class ChatSessionService {
                 const ret = ChatMessageSchema.array().safeParse(messages);
                 if (ret.success) {
                   // render system prompt
-                  const preload = withPrompt
+                  const preload = options?.withPrompt
                     ? prompt
                         .finish(ret.data[0]?.params || {}, id)
                         .filter(({ role }) => role !== 'system')