Add instructions for setting up local Keycloak instance

[kmichalikk]

This pull request includes significant updates to the docs/backend/for_developers.md file to add instructions for setting up Keycloak for SSO login, and a small change to the pyproject.toml file to add a new configuration option.

Documentation updates:

• docs/backend/for_developers.md: Added detailed instructions for setting up Keycloak, configuring the realm, client, and user, and setting environment variables for both front-end and back-end.

Configuration updates:

• pyproject.toml: Added a new configuration option package-mode set to false.

[Copilot]

Pull Request Overview

This PR adds detailed instructions for setting up a local Keycloak instance to support SSO login.

• Introduces a new section in the developer documentation outlining steps for running Keycloak via Docker.
• Provides detailed configuration steps for the realm, client, user, token mapping, and required environment variable setup for both front-end and back-end.

[Copilot]

Consider changing 'is' to 'are' to improve grammatical accuracy ('localhost and 127.0.0.1 are NOT interchangeable').

Suggested change

	**Notice that `localhost` and `127.0.0.1` is NOT interchangeable, use the same URL when you navigate to your app in the browser**
	**Notice that `localhost` and `127.0.0.1` are NOT interchangeable, use the same URL when you navigate to your app in the browser**

[Copilot]

Pull Request Overview

This PR adds detailed instructions for setting up a local Keycloak instance to support SSO login and makes a minor configuration update in the project file.

• Added a new section in the developer documentation outlining steps to set up and configure a local Keycloak instance using Docker.
• Updated the pyproject.toml file by adding a new configuration flag.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
pyproject.toml	Added a new configuration flag (package-mode) to the project configuration.
docs/backend/for_developers.md	Added comprehensive instructions for setting up a local Keycloak instance for SSO support.

Comments suppressed due to low confidence (1)

pyproject.toml:5

• [nitpick] Please confirm that 'package-mode' is the intended configuration property name and adheres to the project naming conventions, as some systems might expect an underscore (e.g., package_mode).

package-mode = false