lutece-solr-indexer

# Lutece 8 Solr Indexer Module

> Before implementing a Solr indexer, consult `~/.lutece-references/lutece-search-module-forms-solr/` — the reference implementation. The main plugin is at `~/.lutece-references/lutece-search-plugin-solr/`.

## Architecture Overview

```
plugin-solr (provides framework — already deployed)
    ↓ auto-discovers via CDI
module-myentity-solr (@ApplicationScoped SolrIndexer)
    ↓ builds
SolrItem (core fields + dynamic fields)
    ↓ writes via
SolrIndexerService.write(Collection<SolrItem>)
    ↓ committed to
Solr Server (HTTP/2 client)

Incremental path:
Entity CRUD → CDI ResourceEvent
    ↓ observed by
SolrEventRessourceListener (plugin-solr, queues SolrIndexerAction in DB)
    ↓ processed by
SolrIndexerDaemon → calls indexer.getDocuments(id)
```

A module provides a `SolrIndexer` implementation. The plugin-solr framework handles server communication, daemon scheduling, and action queue management.

**CDI auto-discovery** — any `@ApplicationScoped` class implementing `SolrIndexer` is automatically registered:
```java
// Inside SolrIndexerService (plugin-solr)
CDI.current( ).select( SolrIndexer.class ).stream( ).toList( );
```

## Step 1 — Maven Module Setup

```xml
<parent>
    <groupId>fr.paris.lutece.plugins</groupId>
    <artifactId>lutece-search-module-myentity-solr</artifactId>
</parent>

<dependencies>
    <dependency>
        <groupId>fr.paris.lutece.plugins</groupId>
        <artifactId>plugin-solr</artifactId>
        <version>[5.0.0-SNAPSHOT,)</version>
        <type>lutece-plugin</type>
    </dependency>
    <dependency>
        <groupId>fr.paris.lutece.plugins</groupId>
        <artifactId>plugin-myentity</artifactId>
        <version>[X.0.0-SNAPSHOT,)</version>
        <type>lutece-plugin</type>
    </dependency>
</dependencies>
```

## Step 2 — SolrIndexer Implementation

```java
import jakarta.enterprise.context.ApplicationScoped;
import jakarta.inject.Inject;
import jakarta.enterprise.inject.Instance;

import fr.paris.lute