feat: add shelly plugin

[joshuaslate]

Plugin

• Id: joshuaslate/shelly
• New plugin
• Update to an existing plugin (version bumped in plugin.toml)

What it does

It uses Shelly to display a list of available updates to the user on a bar widget, then shows more detail in a tooltip, and finally, allows them to configure a click action to either open the CLI and upgrade or open the GUI.

External dependencies

• (Shelly)[https://github.com/Seafoam-Labs/Shelly-ALPM]

Testing

I ran the plugin with the different configurations.

• Tested on Niri
• Tested on Hyprland
• Tested on Sway
• Tested on another compositor:
• Noctalia version tested against: 5

Screenshots / Videos

Checklist

• The directory name matches the part of id after the / in plugin.toml exactly.
• It ships plugin.toml, README.md, thumbnail.webp, and translations/en.json.
• version follows semver and is bumped in this PR; min_noctalia is the version I tested against.
• I only added or edited translations/en.json (no machine-translated locales).
• I did not edit catalog.toml; CI generates it.
• This PR touches exactly one plugin directory.

Code review attestation

Plugins run as trusted, unsandboxed Luau in the user's session. Confirm:

• The code is readable and not obfuscated, minified, or generated.
• It does not download and execute remote code. -- The user will have to provide a password, even with the shelly upgrade-all flow, so nothing happens without their direct action or permission.
• Every network call, filesystem write, and spawned process is something the description above accounts for.
• I have the right to publish this code under the license declared in plugin.toml.