[feature]: Add hide-when-unused toggle for bar widget in screen toolkit

[Ahmed5Emad]

Plugin

• Id: <author>/<plugin>

• New plugin
• Update to an existing plugin (version bumped in plugin.toml)

What it does

External dependencies

Testing

• Tested on Niri
• Tested on Hyprland
• Tested on Sway
• Tested on another compositor:
• Noctalia version tested against:
• Plugin API level:

Screenshots / Videos

Checklist

Ready-for-review requirement: Every box in this section must be checked. If any statement is not true, keep the
pull request as Draft. An explanation does not replace a required check.

• 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.
• README.md follows the
  README template, documents
  every entry id and dependency, and includes exact panel IPC commands and launcher prefixes where applicable.
• I created thumbnail.webp with the thumbnail generator.
• version follows semver and is bumped in this PR; plugin_api is the oldest API level this plugin requires.
• Every non-English translation in this PR uses a locale supported by Noctalia core, and I can read, write, and
  understand that language well enough to review and maintain it (no unreviewed machine/LLM translations).
• 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:
Ready-for-review requirement: Every attestation below must be checked.

• The code is readable and not obfuscated, minified, or generated.
• It does not download and execute remote code.
• 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.

[github-actions]

This pull request was automatically closed because its description no longer contains
every part of the pull request template
that this repository requires.

Missing:

• exactly one checked plugin type: New plugin or Update to an existing plugin
• at least one checked compositor testing entry
• the checked checklist entry: The directory name matches the part of id after the / in plugin.toml exactly.
• the checked checklist entry: It ships plugin.toml, README.md, thumbnail.webp, and translations/en.json.
• the checked checklist entry: README.md follows the README template, documents every entry id and dependency, and includes exact panel IPC commands and launcher prefixes where applicable.
• the checked checklist entry: I created thumbnail.webp with the thumbnail generator.
• the checked checklist entry: version follows semver and is bumped in this PR; plugin_api is the oldest API level this plugin requires.
• the checked checklist entry: Every non-English translation in this PR uses a locale supported by Noctalia core, and I can read, write, and understand that language well enough to review and maintain it (no unreviewed machine/LLM translations).
• the checked checklist entry: I did not edit catalog.toml; CI generates it.
• the checked checklist entry: This PR touches exactly one plugin directory.
• the checked checklist entry: The code is readable and not obfuscated, minified, or generated.
• the checked checklist entry: It does not download and execute remote code.
• the checked checklist entry: Every network call, filesystem write, and spawned process is something the description above accounts for.
• the checked checklist entry: I have the right to publish this code under the license declared in plugin.toml.

Please add the items listed above back to the description, keeping their exact wording, then
reopen the pull request. Reopening re-runs this check. Draft pull requests may leave boxes
unchecked. Before a pull request is ready for review, exactly one plugin type, at least one
tested compositor, and every item under Checklist and Code review attestation must be checked.