fix(apps): make app CMakeLists out-of-tree build safe

[yingtao450]

add_subdirectory() with an absolute ${APP_PATH}/... source dir needs an explicit binary directory when the app is built out-of-tree (copied into a project's source/embedded and include()'d by the SDK from outside the SDK source tree). Otherwise CMake errors: "add_subdirectory not given a binary directory ... is not a subdirectory of ...".

Give each such call a unique ${CMAKE_BINARY_DIR}/app_ binary dir:

• apps/tuya.ai/your_chat_bot (display2, battery)
• apps/tuya.ai/your_robot_dog (display)
• apps/tuya.ai/your_serial_chat_bot (battery)
• apps/tuya_t5_pocket/tuya_t5_pocket_ai (display x2 exclusive branches, expand)
• examples/tflite/tflite-helloworld (tflite)

PR 描述/PR description

[在此详细描述 PR 的内容]/[Describe the PR content in detail here]

代码质量/Code Quality:

在本次拉取请求中，我已考虑以下事项 As part of this pull request, I've considered the following:

• 确保代码注释和文档清晰，并使用英文注释以保证代码可读性。Ensure that the code comments and documentation are clear, and use English for comments to ensure code readability.
• 确保文件头遵循文件头格式。Ensure that the file header follows the File Header Format.
• 确保函数头遵循 Doxygen 格式。Ensure that function headers follow the Doxygen format as specified in Comments.
• 已查阅 编码风格指南，并核查代码风格合规性，包括缩进、空格、命名规范及其他风格要求。 Reviewed the Coding Style Guide and verified code style compliance, including indentation, spacing, naming conventions, and other style guidelines.
• 已使用代码格式化工具确保符合 TuyaOpen 编码规范。Have used the code-formatting source code formatting tool to ensure compliance with TuyaOpen coding standards.