Add Keyviz Plugin - #450

the `- **Id:**` field; the `- **Noctalia version tested against:**` field; the `- **Plugin API level:**` field; the checklist entry: New plugin; the checklist entry: Update to an existing plugin (version bumped in `plugin.toml`); the checklist entry: Tested on Niri; the checklist entry: Tested on Hyprland; the checklist entry: Tested on Sway; the checklist entry: Tested on another compositor:; the checklist entry: The directory name matches the part of `id` after the `/` in `plugin.toml` exactly.; the checklist entry: It ships `plugin.toml`, `README.md`, `thumbnail.webp`, and `translations/en.json`.; the checklist entry: `README.md` follows the [README template](https://github.com/noctalia-dev/community-plugins/blob/main/README_TEMPLATE.md), documents every entry id and dependency, and includes exact panel IPC commands and launcher prefixes where applicable.; the checklist entry: I created `thumbnail.webp` with the [thumbnail generator](https://assets.noctalia.dev/plugins/thumbnail-generator.html).; the checklist entry: `version` follows semver and is bumped in this PR; `plugin_api` is the oldest API level this plugin requires.; the 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 checklist entry: I did not edit `catalog.toml`; CI generates it.; the checklist entry: This PR touches exactly one plugin directory.; the checklist entry: The code is readable and not obfuscated, minified, or generated.; the checklist entry: It does not download and execute remote code.; the checklist entry: Every network call, filesystem write, and spawned process is something the description above accounts for.; the checklist entry: I have the right to publish this code under the `license` declared in `plugin.toml`.; exactly one checked plugin type: New plugin or Update to an existing plugin; at least one checked compositor testing entry