fix: restore brainstorming feature with missing socket server and real-time events

memento-note/app/api/brainstorm/[sessionId]/convert/route.ts

@@ -2,6 +2,8 @@ import { NextRequest, NextResponse } from 'next/server'
 import prisma from '@/lib/prisma'
 import { auth } from '@/auth'
 import { z } from 'zod'
+import { logActivity } from '@/lib/brainstorm-collab'
+import { emitToSession } from '@/lib/socket-emit'
 
 const convertSchema = z.object({
   ideaId: z.string().min(1),
@@ -153,6 +155,15 @@ export async function POST(
 
     await prisma.$transaction(tagPromises)
 
+    await logActivity(sessionId, 'idea_converted', session.user.id, { ideaTitle: idea.title, ideaId: idea.id, noteId: note.id })
+
+    await emitToSession(sessionId, 'activity:new', {
+      action: 'idea_converted',
+      userId: session.user.id,
+      userName: session.user.name || 'Guest',
+      details: { ideaTitle: idea.title, ideaId: idea.id, noteId: note.id }
+    })
+
     return NextResponse.json({ success: true, data: note }, { status: 201 })
   } catch (error: any) {
     if (error instanceof z.ZodError) {