Add GitHub Action to publish releases to Play Store Internal Test track

[Copilot]

Why is this important?

Automates Play Store deployments similar to existing Firebase App Distribution workflow. All Q42 apps use Play Store, so automating pushes to internal test track eliminates manual upload steps.

Notes

New workflow: .github/workflows/playstore-internal.yml

• Triggers on release/** branches and manual dispatch
• Builds signed AAB using existing keystore secrets
• Uploads to Play Store Internal Test track via r0adkll/upload-google-play@v1
• Sets inAppUpdatePriority: 2 and status: completed

Setup required:

• Add PLAYSTORE_SERVICE_ACCOUNT_JSON secret (service account with Play Developer API access)
• Update packageName: nl.q42.template to your app's package name (see "Using this template" section in README)

Documentation updates:

• Added Play Store deployment section with setup instructions and link to upload-google-play action configuration guide
• Added explicit reminder in "Using this template" section to update packageName in workflow file after running rename-project.py
• Fixed workflow comment typos and updated references from APK to AAB

Security:

• Explicit permissions: contents: read to limit GITHUB_TOKEN scope
• CodeQL validated, no alerts

Original prompt

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This section details on the original issue you should resolve

<issue_title>Github Action to publish release to Playstore Internal Test track</issue_title>
<issue_description>We currently have a Github action to push releases to Firebase App Distribution.

Since 100% of our apps use play store obviously, it might be nice to automate andy pushes to a release branch to the internal test track of a connected Play Store app.

To implement this, I'd say it is fine to create a dummy app q42.template in hte play console and simply don't release it to production; just internal test track</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Github Action to publish release to Playstore Internal Test track #108

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[ninovanhooff]

Tragically, the template's package name is already taken, not sure if I registered it sometime ago or someone else. But it is blocking publishing of the app. (also manually this is not possible)

Changing the package name would mean changing the rename-project.py too. this is possible but feels a bit heavy handed

[Copilot]

Tragically, the template's package name is already taken, not sure if I registered it sometime ago or someone else. But it is blocking publishing of the app. (also manually this is not possible)

Ch...

Added an explicit reminder in the "Using this template" section (commit 3cc42e5) to update the packageName in the workflow file after running rename-project.py. Since this is a template, users are expected to customize the package name - the workflow includes a TODO comment and the README now has clear instructions in both the setup section and the Play Store deployment section.

[ninovanhooff]

Although we can sadly not use this to publish the template app itself due to the package id already being taken on the play store, I used this for an actual project, which worked fine. I think we can merge this