feat: add slides generation tool with multiple slide types

- Add slides.tool.ts with support for title, bullets, chart, stats, table, cards, timeline, quote, comparison, equation, image, summary slide types
- Chart types: bar, horizontal-bar, line, donut, radar
- Integrate with agent executor and canvas system
- Add multilingual support (en/fr)
- Various UI improvements and bug fixes

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

memento-note/app/api/notebooks/route.ts

@@ -1,7 +1,9 @@
 import { NextRequest, NextResponse } from 'next/server'
+import { Prisma } from '@prisma/client'
 import prisma from '@/lib/prisma'
 import { auth } from '@/auth'
 import { revalidatePath } from 'next/cache'
+import { CreateNotebookSchema } from '@/lib/validators'
 
 const DEFAULT_COLORS = ['#3B82F6', '#8B5CF6', '#EC4899', '#F59E0B', '#10B981', '#06B6D4']
 const DEFAULT_ICONS = ['📁', '📚', '💼', '🎯', '📊', '🎨', '💡', '🔧']
@@ -63,11 +65,14 @@ export async function POST(request: NextRequest) {
 
   try {
     const body = await request.json()
-    const { name, icon, color, parentId } = body
-
-    if (!name || typeof name !== 'string') {
-      return NextResponse.json({ success: false, error: 'Notebook name is required' }, { status: 400 })
+    const parsed = CreateNotebookSchema.safeParse(body)
+    if (!parsed.success) {
+      return NextResponse.json(
+        { success: false, error: 'Invalid request body', details: parsed.error.flatten() },
+        { status: 400 }
+      )
     }
+    const { name, icon, color, parentId } = parsed.data
 
     if (parentId) {
       const parent = await prisma.notebook.findFirst({
@@ -78,9 +83,7 @@ export async function POST(request: NextRequest) {
       }
     }
 
-    const whereClause: any = { userId: session.user.id }
-    if (parentId) whereClause.parentId = parentId
-    else whereClause.parentId = null
+    const whereClause: Prisma.NotebookWhereInput = { userId: session.user.id, parentId: parentId ?? null }
 
     const highestOrder = await prisma.notebook.findFirst({
       where: whereClause,