Add Game Theme Song

[BambooFury]

Game Theme Song

Automatically plays each game's theme music in the background when you open its page in your Steam library. Runs fully client-side with a standard Millennium Lua backend and a TypeScript frontend — no external services, no account credentials stored beyond the active Steam session.

Features:

• Automatic per-game theme lookup from soundtrack sources (Khinsider, SoundCloud) with candidate scoring, so only confident OST picks are kept
• Music note button on every game page opens a native popup with Now Playing, Settings, Downloaded and Custom Music tabs
• Per-game custom tracks stored in a dedicated folder that survives plugin reinstall — restored automatically after installing again
• Volume slider, loop, song length limit, stop-on-launch, manual search and confirm-before-keep settings
• Live downloaded track counts and sizes

Task Checklist

Developer

• I am the original author or an authorized maintainer of this plugin.
• I have complied with all license requirements for the libraries used, including providing appropriate notices where necessary.
• My plugin is fully open source and does not depend on any external paid services, except for widely trusted and well-known platforms. Additionally, neither I nor anyone associated with me profits from any such services.

Plugin Functionality

• My plugin is unique, or provides additional or alternative functionality to plugins already on the store.

Backend Configuration

• I use a standard Millennium Lua backend in my plugin.
• I use custom binaries that or rely on other FOSS projects that aren't written directly using Millennium's Lua backend.

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Testing Instructions

1. Install the plugin from the store and restart Steam.
2. Open any game page in your library — its theme music starts playing automatically and a music note button appears on the page.
3. Click the note button to open the popup: control playback, keep or skip tracks, adjust settings, and manage downloaded or custom music.

[github-actions]

This pull request was closed because the plugin failed to build. See the build log for details. Fix the issue and reopen this pull request to retry the build.

[BambooFury]

Really cool.

[BambooFury]

@ejalxndr Will you be able to open it? I'll fix the issue that caused the error.

[ejalxndr]

I can re-open the PR once its fixed!