docs: licensing, credits & demo GIF

LICENSE

@@ -186,7 +186,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright [yyyy] [name of copyright owner]
+   Copyright 2026 The ComposeReels Authors
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

NOTICE

@@ -0,0 +1,29 @@
+ComposeReels
+Copyright 2026 The ComposeReels Authors
+
+This product is licensed under the Apache License, Version 2.0 (see LICENSE).
+
+------------------------------------------------------------------------
+Third-party dependencies
+------------------------------------------------------------------------
+This product depends on open-source libraries distributed under permissive
+licenses (Apache-2.0 / MIT), including AndroidX & Jetpack Compose, Dagger
+Hilt, AndroidX Media3 (ExoPlayer), Coil, Retrofit, OkHttp, and the Kotlin
+and kotlinx libraries. Each retains its own copyright and license.
+
+------------------------------------------------------------------------
+Sample media (referenced by URL for demonstration only; NOT covered by the
+Apache-2.0 license above and NOT redistributed in this repository)
+------------------------------------------------------------------------
+- "Big Buck Bunny" and "Sintel" — (c) Blender Foundation,
+  https://www.blender.org, licensed under Creative Commons Attribution 3.0
+  (CC BY 3.0): https://creativecommons.org/licenses/by/3.0/
+- HLS test stream "BipBop" — (c) Apple Inc., provided as a public test asset.
+- HLS test stream from Mux (https://test-streams.mux.dev), provided as a
+  public test asset.
+- Placeholder thumbnail images from Lorem Picsum (https://picsum.photos),
+  sourced from Unsplash (https://unsplash.com/license).
+
+All trademarks are the property of their respective owners. ComposeReels is
+not affiliated with, endorsed by, or sponsored by TikTok, Instagram, Google,
+Apple, Mux, or the Blender Foundation.

README.ja.md

@@ -31,10 +31,11 @@ Google が推奨する技術スタックとアーキテクチャだけで作っ
 - 🤖 **AI フレンドリー** — [`CLAUDE.md`](CLAUDE.md) に規約を明文化し、AI エージェント（と人間）が
   安心して拡張できます。
 
-## 📸 スクリーンショット
+## 🎬 デモ
 
-<!-- TODO: リールフィードのスクリーン録画 / GIF をここに追加 -->
-_ここにデモ GIF を追加してください。_
+<p align="center">
+  <img src="docs/demo.gif" alt="ComposeReels デモ — リールフィードのスワイプ" width="280" />
+</p>
 
 ## 🏛️ アーキテクチャ
 
@@ -141,11 +142,25 @@ convention plugins。
 歓迎します。[CONTRIBUTING.md](CONTRIBUTING.md) と
 [行動規範](CODE_OF_CONDUCT.md) をご覧ください。
 
-## 📄 ライセンス
+## 🎞️ クレジット・サードパーティ素材
+
+サンプルリールは**デモ目的で URL 参照しているだけ**で、リポジトリには再配布しておらず、
+**本プロジェクトのライセンス対象外**です:
+
+- **Big Buck Bunny** / **Sintel** — © [Blender Foundation](https://www.blender.org)、
+  [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) で提供。
+- **BipBop** HLS テストストリーム — © Apple Inc.（公開テスト素材）。
+- [Mux](https://test-streams.mux.dev) の HLS テストストリーム（公開テスト素材）。
+- サムネのプレースホルダは [Lorem Picsum](https://picsum.photos)（画像は
+  [Unsplash](https://unsplash.com/license) 由来）。
 
-[Apache License 2.0](LICENSE) のもとで公開しています。
+サードパーティのライブラリは各自のライセンス（Apache-2.0 / MIT）に従います。[NOTICE](NOTICE) を参照。
+
+各商標は各社に帰属します。ComposeReels は TikTok / Instagram / Google / Apple / Mux /
+Blender Foundation と**提携・承認・出資関係はありません**。
+
+## 📄 ライセンス
 
-サンプル動画の著作権は各権利者（Blender Foundation のオープンムービー、Apple・Mux の HLS
-テストストリーム）に帰属し、デモ目的でのみ使用しています。
+[Apache License 2.0](LICENSE) のもとで公開しています（[NOTICE](NOTICE) も参照）。
 
 [nia]: https://github.com/android/nowinandroid

README.md

@@ -32,10 +32,11 @@ so coding agents (and people) can extend it confidently.
 - 🤖 **AI-ready** — a [`CLAUDE.md`](CLAUDE.md) documents the conventions so AI agents (and humans)
   can extend the project confidently.
 
-## 📸 Screenshots
+## 🎬 Demo
 
-<!-- TODO: add a screen recording / GIF of the reels feed here. -->
-_Add a demo GIF here._
+<p align="center">
+  <img src="docs/demo.gif" alt="ComposeReels demo — swiping through the reels feed" width="280" />
+</p>
 
 ## 🏛️ Architecture
 
@@ -141,11 +142,25 @@ convention plugins.
 Contributions are welcome — see [CONTRIBUTING.md](CONTRIBUTING.md) and our
 [Code of Conduct](CODE_OF_CONDUCT.md).
 
-## 📄 License
+## 🎞️ Credits & third-party assets
+
+The sample reels are **referenced by URL for demonstration only** — they are not redistributed in
+this repository and are **not covered by this project's license**:
+
+- **Big Buck Bunny**, **Sintel** — © [Blender Foundation](https://www.blender.org), licensed under
+  [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/).
+- **BipBop** HLS test stream — © Apple Inc. (public test asset).
+- HLS test stream from [Mux](https://test-streams.mux.dev) (public test asset).
+- Placeholder thumbnails from [Lorem Picsum](https://picsum.photos) (images from
+  [Unsplash](https://unsplash.com/license)).
 
-Licensed under the [Apache License 2.0](LICENSE).
+Third-party libraries retain their own licenses (Apache-2.0 / MIT). See [NOTICE](NOTICE).
+
+All trademarks are the property of their respective owners. ComposeReels is **not affiliated with,
+endorsed by, or sponsored by** TikTok, Instagram, Google, Apple, Mux, or the Blender Foundation.
+
+## 📄 License
 
-Sample videos © their respective owners (Blender Foundation open movies; Apple and Mux HLS test
-streams), used here for demonstration purposes only.
+Licensed under the [Apache License 2.0](LICENSE); see also [NOTICE](NOTICE).
 
 [nia]: https://github.com/android/nowinandroid