android/sunflower ? reverse-engineered prompt

Build me an Android gardening app called Sunflower that helps people browse plants, learn about them, and save ideas for their garden.

I want it to feel modern and polished, using Jetpack Compose with Material 3, and it should clearly look like a simple sample app for best practices. Include a home screen with plant information, a plant detail page with a nice image and readable description, and a gallery area that can show photos from Unsplash if I add an API key. If the key is missing, the app should still work and just skip the gallery part.

Keep the experience clean and easy to use, with good navigation between screens and a layout that works well on Android phones. I also want the code to be set up like a real sample project that shows how to migrate a View based app to Compose. If you need current docs or API details, look them up online while you build it.