Feature: added custom app example using React 19

[MartinaeyNL]

Description

This PR adds a React example app to the /ui/app directory.
It is meant as a 'quick start' for developers to work on custom apps using React.

The app in itself is very basic, with;

• An initial login screen prompt, asking to login in the master realm of an instance.
• A connection to the OpenRemote websocket and HTTP API (along with token management).
• A template page with a button that links to the OpenRemote documentation.
• Configurations for improved local React development

[MartinaeyNL]

Currently in a state of early setup.

We'll need to discuss what functionalities this custom app should have,
or whether it's a simple template for other developers to move forward with.

[MartinaeyNL]

Code is ready to be reviewed.

PR is blocked by openremote/openremote#2216, to export JSX types for the OpenRemote components.

[MartinaeyNL]

The PR on the OpenRemote repository has been merged! Great!
Now we'll wait until a release, so I can continue this branch.

[MartinaeyNL]

Ready for review! I've updated the description to a proper one.
Let me know if anyone is OK with reviewing this 👍

[Copilot]

Pull Request Overview

This PR adds a React 19 example application to the /ui/app/custom-react directory as a quick-start template for developers building custom OpenRemote applications. The PR also updates OpenRemote package versions from 1.10.0 to 1.11.0 across the codebase.

Key changes:

• New React 19 application with Rspack bundler configuration
• Manager connection setup with Keycloak authentication
• Updated dependency versions across all packages (OpenRemote 1.10.0 → 1.11.0, Rspack 1.4.11 → 1.6.0)

Reviewed Changes

Copilot reviewed 16 out of 19 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
ui/app/custom-react/*	New React 19 example app with TypeScript, including source files, configuration, and build setup
ui/app/README.md	Enhanced documentation describing both custom app examples (Lit and React)
yarn.lock	Updated dependencies for OpenRemote packages (1.11.0), Rspack (1.6.0), and React 19 support
ui/app/custom/package.json	Updated OpenRemote and Rspack package versions
ui/component/*/package.json	Updated OpenRemote utility package versions
package.json	Updated root OpenRemote utility package version
gradle.properties	Updated OpenRemote version to 1.11.0

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[MartinaeyNL]

Resolved the comments by Copilot.
Also addressed an issue where importing assets was not working correctly, so I adjusted the RSPack configuration.
It should now all work correctly, and is ready to be reviewed! 👍