Make system labels configurable

[AlaeMghirbi]

Why?

Current problem: The needs-action label is hard-coded
private static final String NEEDS_ACTION = "needs-action";
Problems identified: Different use cases may require different system labels and needs (e.g., "promotion", "social", "to-do") => needs action is not the only possible scenario.
Also system administrators should be able to control system labels without modifying the code

What?

We want to make system labels configurable through the application configuration file, not hard-coded.
Goal: Configuration-driven system labels

1. Define system labels in listeners.xml configuration
2. Support multiple system labels (not just needs-action)
3. Each system label has: id, displayName, color, description

We also want to have clear separation between:

• System labels: Configured in listeners.xml (managed by admins)
• User labels: Stored in database (managed by users via JMAP)

System labels are configuration and they should not be stored in database

Example:

    <listener>
        <class>com.linagora.tmail.listener.rag.LlmMailClassifierListener</class>
        <configuration>
                     ....
              <systemLabels>
                <label>
                  <id>needs-action</id>
                  <displayName>Needs Action</displayName>
                  <color>#FF6B6B</color>
                  <description>Email requires the recipient to take action: answer a question, make a decision, complete a task, handle a request, or respond by a deadline.</description>
                </label>
                 <label>
                  <id>promotional</id>
                  <displayName>Promotional</displayName>
                  <color>#4ECDC4</color>
                  <description>Marketing, newsletters, announcements, or promotional content.</description>
                </label>
              </systemLabels>
        </configuration>
    </listener>

How:

• Create SystemLabel record that create systemLabel from configuration and can turn it into an actual Label .
• Label ID validation should include both user and system labels before being added as a flag.

[chibenwa]

While this is tempting to put labels in LlmMailClassifierListener config now, this will sinergize very badly with exposing them at the JMAP level.

How about:

jmap.properties:

labels.needs-action.display-name=Needs Action
labels.needs-action.colour=#FF6B6B
labels.needs-action.flag=needs-action
labels.needs-action.description=Email requires the recipient to take action: answer a question, make a decision, complete a task, handle a request, or respond by a deadline.

labels.promotional.display-name=Promotional
labels.promotional.colour=#4ECDC4
labels.promotional.flag=promotional
labels.promotional.description=Marketing, newsletters, announcements, or promotional content.

We could then build from this configuration a SystemLabelsProvider that could be reused in the JMAP layer and in our LLM classifier code?

And we need the system flag alongside it.