Add QR Code Encoder plugin

[Yocraft-2000]

Plugin

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

What it does

Transform any text or URL into a QR code completely offline. Then scan or copy the code.

External dependencies

qrencode

Testing

• Tested on Niri
• Tested on Hyprland
• Tested on Sway
• Tested on another compositor:
• Noctalia version tested against: v5.0.0
• Plugin API level: 15

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.
• 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:

• 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.

[ItsLemmy]

1. blocking - qrcode/plugin.toml:24

The custom_image widget setting uses type = "image", which the repository validator does not support.
Use "file" instead

[[widget.setting]]
key = "custom_image"
type = "file"
label_key = "widget.custom_image.label"
description_key = "widget.custom_image.description"
default = ""
extensions = [".png", ".jpg", ".jpeg", ".webp", ".svg"]

2. non-blocking - qrcode/panel.luau:105

generate() shell-escapes the trimmed input before checking whether it is empty. Empty or whitespace-only input becomes "''", so the branch at qrcode/panel.luau:107 is unreachable. Submitting empty input invokes qrencode and reports a generation error instead of clearing the existing image and returning to the idle state.