Setup ios builds, setup basic customizations

[mykhailodanilenko]

🚀 Description

This PR changes the application to be configurable from a configuration .env file, as well as introducing a job of building the .app iOS simulator app to the pipeline.
You can go to https://mykhailodanilenko.github.io/web-client/ and observe a custom icon as well as app name on the homepage, other artifacts are also available at https://github.com/mykhailodanilenko/web-client/actions/runs/11628293461.

📄 Motivation and Context

#202 and #18

🧪 How Has This Been Tested?

• Web (desktop)
• Web (mobile)
• Mobile (iOS)
• Mobile (Android)

📦 Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

✅ Checklist (copied from README)

• Squash your changes into a single clear and thoroughly descriptive commit, split changes into multiple commits only when it contributes to readability
• Reference the GitHub issue that you are contributing on in your commit title or body
• Sign your commits, as this is required by the automated GitHub PR checks
• Ensure that the changes adhere to the project code style and formatting rules by running npx eslint . and npx prettier --check ../ from the ./OwnTube.tv/ directory (without errors/warnings)
• Include links and illustrations in your pull request to make it easy to review
• Request a review by @mykhailodanilenko, @ar9708 and @mblomdahl

[mblomdahl]

Really cool! I downloaded the build from your GHA pipeline and installed it on my iPhone simulator. Works great!

[mblomdahl]

Looks great! As a follow-up task, can we update the README with what needs to be done to build it?