feat(niri-displays): add rotation, position, and display layout

[psukez]

Plugin

• Id: raycursive/niri-displays
• New plugin
• Update to an existing plugin (version bumped in plugin.toml)

What it does

Adds rotation (transform), position, and a unified Display layout panel to the existing niri-displays plugin.

• Rotation — rotate any connected output (0°/90°/180°/270°) through Niri's transform IPC.
• Position — move an output to any side of another output (top / left / right / bottom) plus a fine-grained pixel offset, through Niri's position IPC.
• Display layout — one unified panel to pick the output, place it with a button cross, fine-tune with a single offset slider, and apply with one button.

Users get full temporary control over how their monitors are arranged and oriented, directly from the Noctalia panel, without editing config.kdl.

External dependencies

• niri — the plugin shells out to niri msg to read output state (niri msg --json outputs, niri msg --json focused-output) and to apply changes (niri msg output <connector> mode/scale/transform/position ...). Listed in plugin.toml under dependencies.

Testing

• Tested on Niri
• Tested on Hyprland
• Tested on Sway
• Tested on another compositor:
• Noctalia version tested against: v5.0.0 (v5.0.0-beta.9-3-g69a90183531d)
• Plugin API level: 9

Screenshots / Videos

The unified Display layout panel:

The panel with the new rotation, position, and display-layout controls:

Checklist

Ready-for-review requirement: Every box in this section must be checked.

• 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.

[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:

• the template marker line <!-- noctalia-pr-template:v1 -->
• the ## Plugin heading
• the ## What it does heading
• the ## External dependencies heading
• the ## Screenshots / Videos heading
• the ## Checklist heading
• the ## Code review attestation heading
• 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, 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.
• 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

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.

[github-actions]

CC @raycursive