license: add third-party license notices

LICENSE

@@ -210,3 +210,40 @@ Copyright 2025-2026 Sepehr
 Licensed under the Apache License, Version 2.0 with Commons Clause
 Restriction. You may not use this software for commercial purposes
 without explicit written permission from the copyright holder.
+
+---
+
+THIRD-PARTY LICENSES
+
+This software includes or depends on the following third-party packages.
+Each package is licensed under its respective license.
+
+MIT License:
+  - @excalidraw/excalidraw (Copyright Excalidraw)
+  - react (Copyright Meta Platforms, Inc.)
+  - react-dom (Copyright Meta Platforms, Inc.)
+  - next (Copyright Vercel, Inc.)
+  - prisma (Copyright Prisma Data, Inc.)
+  - tailwindcss (Copyright Tailwind Labs)
+  - lucide-react (Copyright Lucide Icons)
+  - nodemailer (Copyright Andris Reinman)
+  - zod (Copyright Colin McDonnell)
+  - bcryptjs (Copyright Nev Dvir)
+  - @modelcontextprotocol/sdk (Copyright Anthropic, PBC)
+  - resend (Copyright Resend, Inc.)
+  - react-markdown (Copyright Espen Hovlandsdal)
+  - remark-gfm (Copyright Titus Wormer)
+  - remark-math (Copyright Titus Wormer)
+  - rehype-katex (Copyright Titus Wormer)
+  - katex (Copyright Khan Academy)
+
+Apache License 2.0:
+  - @ducanh2912/next-pwa (Copyright Duy Canh Le)
+  - next-auth (Copyright Balázs Orbán, Iain Collins)
+
+ISC License:
+  - shadcn/ui components (Copyright shadcn)
+
+All third-party packages retain their original licenses.
+The Commons Clause restriction above applies only to the Memento
+application code, not to the third-party packages listed here.