Add VS Code Dev Container for reproducible development environment

[KidScripty]

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.

Feature description

Summary

Provide a lightweight VS Code devcontainer to simplify onboarding and ensure reproducible builds. The devcontainer will supply a matching JDK and Android SDK components so contributors can build the project without installing them locally.

Scope

• Add a .devcontainer/ folder containing:
  • Dockerfile to install OpenJDK 17 and Android command-line tools.
  • devcontainer.json to expose JAVA_HOME and ANDROID_SDK_ROOT, recommend extensions, and run a post-create script.
  • post-create.sh to accept SDK licenses and install platform-tools, platforms;android-36, and a pinned build-tools version.
• Add a short README note describing how to open the repository in the devcontainer and run a build (./gradlew clean assembleDebug).

Benefits

• Lowers setup friction for contributors.
• Ensures a consistent toolchain (JDK and Android SDK versions).
• Reduces environment-related build failures.

Acceptance criteria

• The repository contains a .devcontainer/ folder with the Dockerfile and devcontainer.json.
• Opening the repo in VS Code Remote-Containers builds the container and enables running the Gradle wrapper to produce a debug APK.
• Documentation briefly explains how to use the devcontainer.

Notes

• First build requires network access to download SDK components.
• Emulators are out-of-scope due to nested virtualization; recommend physical devices or CI-based emulators.
• JDK 17 is recommended because the project targets Java 17 and Kotlin jvmTarget 17.

Contribution caveat

I’m opening this issue with the intent to implement the devcontainer myself, but per the project guidelines contributions must start from a triaged issue—please triage/approve this issue so I can submit a PR.

Why do you want this feature?

Why I want this

• I want to implement the devcontainer myself to learn the repository structure and provide a reproducible environment for contributors.
• It will make it easier for new contributors (including me) to build and test changes without manual JDK/Android SDK setup.
• Once this issue is triaged and approved I will submit a PR that adds the .devcontainer files and a short README

Additional information

• VS Code Dev Containers docs — official guide to authoring and using devcontainers
  https://code.visualstudio.com/docs/devcontainers/containers

• Dev Container specification / ecosystem — tooling and spec references
  https://containers.dev/

• GitHub Codespaces: development environments in a container — explains benefits and practical workflows (good background on why devcontainers help)
  https://docs.github.com/en/codespaces/about-codespaces/what-are-codespaces

[naveensingh]

Android app development is primarily and officially done on Android Studio. You can download it here.

[KidScripty]

Surely having support configuration for devContainers to allow people using VSCode to get up and running seemlessly wouldn't be a negative?

If that's what people prefer to use, and you have no documentation anywhere across the repositories about recommended dev set ups then what would be the issue with this?