Add Easy SteamGrid (Linux)

[UtopicMind]

Adds Easy SteamGrid (Linux) — a SteamGridDB integration plugin for Steam on Linux, applying custom grids, heroes, logos, icons, and wide grids, including animated artwork with zero conversion (no Python/Pillow, no local server).

Not a GitHub fork of the existing steam-easygrid entry — it's an independently maintained repo, though the codebase originated from luthor112/steam-easygrid (credited in the README; MIT license inherited from the original). Named steam-easygrid-linux specifically to avoid colliding with the plugins/steam-easygrid submodule already in this database.

How it differs from the existing steam-easygrid entry

Same core purpose, but a ground-up rewrite of the artwork pipeline: animated WebP renders natively through Steam's own SetCustomArtworkForApp, using SteamGridDB's -fakepng.png CDN variant, so there's no conversion step and no local HTTP server involved at all. On top of that, this adds a couple of community-browsing features the original doesn't have — each result shows the uploader's avatar and name, linking to their SGDB profile, and a live hearts/like count with a working heart button to like directly from the picker.

Core artwork pipeline:

• Chunked IPC transfer supports any file size, applies instantly with no restart required
• Icon support via librarycache overwrite with automatic backup/restore

Community features:

• Each search result shows the uploader's avatar and name, linking directly to their SGDB profile
• Live hearts/like counts per asset, with a working heart button to like directly from the picker

Repo: https://github.com/UtopicMind/steam-easygrid-linux

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

• I have tested the plugin on both the Stable and Beta Steam update channels. (Tested thoroughly on Stable. Attempted on Beta, but Millennium's own client injection didn't apply to that build — a known gap documented in Millennium's own troubleshooting docs, not specific to this plugin.)
• My plugin is unique, or provides additional or alternative functionality to plugins already on the store.

Backend Configuration

• Yes: I use a standard Millennium lua backend in my plugin. — "backendType": "lua" in plugin.json.
• No: I use custom binaries or rely on other FOSS projects not written directly using Millennium's lua backend.

Community Contribution

• I have tested and left feedback on two other plugin pull requests.
• I have added links to those feedback comments in this PR.

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Testing Instructions

Install, restart Steam, enable under Millennium → Plugins, then click any game in your Steam Library, click the "SG" button on that game's page, and choose Open window from the menu that appears:

1. Open the Hero tab for a game with existing SGDB artwork. Thumbnails should load, including animated ones (auto-playing). Click a static one — it should apply instantly, no restart.
2. Click an animated thumbnail — it should apply and actually animate in Steam's own UI, not just show a static frame.
3. Repeat for Grid, Wide Grid, Logo, and Icon tabs.
4. Check the row under each thumbnail — an avatar and uploader name should be present, and clicking it should open that uploader's SGDB profile in your browser.
5. Click a heart on any thumbnail — the count should update and the heart should fill in. Click it again — it should un-heart and the count should drop back down.
6. Type a numeric ID into the SGDB ID field and click Set SGDB ID — subsequent searches should use that ID instead of the auto-matched one.
7. Click Purge All Cache, then reopen a picker — artwork should re-download rather than serve from a stale cache.

• Verified by a third party on Steam Client Stable.
• Verified by a third party on Steam Client Beta.