feat(api): DTOs et enums pour système de messagerie

Ajout des DTOs et enums nécessaires au système de communication/messaging.

Enums (communication):
- ConversationType: INDIVIDUAL, GROUP, BROADCAST, ANNOUNCEMENT
- MessageType: INDIVIDUAL, BROADCAST, TARGETED, SYSTEM
- MessageStatus: SENT, DELIVERED, READ, FAILED
- MessagePriority: NORMAL, HIGH, URGENT

DTOs Request:
- CreateConversationRequest: name, description, type, participantIds, organisationId
- SendMessageRequest: conversationId, content, type, priority, recipientIds, etc.

DTOs Response:
- ConversationResponse: données complètes conversation + lastMessage + unreadCount
- MessageResponse: données complètes message

Tâche: #60 - Communication Backend (Part 1/2 - API)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/main/java/dev/lions/unionflow/server/api/dto/communication/request/CreateConversationRequest.java

@@ -0,0 +1,27 @@
+package dev.lions.unionflow.server.api.dto.communication.request;
+
+import dev.lions.unionflow.server.api.enums.communication.ConversationType;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotEmpty;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+import lombok.Builder;
+
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * Request DTO pour créer une conversation
+ *
+ * @author UnionFlow Team
+ * @version 1.0
+ * @since 2026-03-16
+ */
+@Builder
+public record CreateConversationRequest(
+    @NotBlank @Size(max = 255) String name,
+    @Size(max = 1000) String description,
+    @NotNull ConversationType type,
+    @NotEmpty List<UUID> participantIds,
+    UUID organisationId
+) {}

src/main/java/dev/lions/unionflow/server/api/dto/communication/request/SendMessageRequest.java

@@ -0,0 +1,29 @@
+package dev.lions.unionflow.server.api.dto.communication.request;
+
+import dev.lions.unionflow.server.api.enums.communication.MessagePriority;
+import dev.lions.unionflow.server.api.enums.communication.MessageType;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+import lombok.Builder;
+
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * Request DTO pour envoyer un message
+ *
+ * @author UnionFlow Team
+ * @version 1.0
+ * @since 2026-03-16
+ */
+@Builder
+public record SendMessageRequest(
+    @NotNull UUID conversationId,
+    @NotBlank @Size(max = 10000) String content,
+    MessageType type,
+    MessagePriority priority,
+    List<UUID> recipientIds,
+    List<String> recipientRoles,
+    List<String> attachments
+) {}

src/main/java/dev/lions/unionflow/server/api/dto/communication/response/ConversationResponse.java

@@ -0,0 +1,33 @@
+package dev.lions.unionflow.server.api.dto.communication.response;
+
+import dev.lions.unionflow.server.api.enums.communication.ConversationType;
+import lombok.Builder;
+
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * Response DTO pour Conversation
+ *
+ * @author UnionFlow Team
+ * @version 1.0
+ * @since 2026-03-16
+ */
+@Builder
+public record ConversationResponse(
+    UUID id,
+    String name,
+    String description,
+    ConversationType type,
+    List<UUID> participantIds,
+    UUID organisationId,
+    MessageResponse lastMessage,
+    int unreadCount,
+    boolean isMuted,
+    boolean isPinned,
+    boolean isArchived,
+    LocalDateTime createdAt,
+    LocalDateTime updatedAt,
+    String avatarUrl
+) {}

src/main/java/dev/lions/unionflow/server/api/dto/communication/response/MessageResponse.java

@@ -0,0 +1,39 @@
+package dev.lions.unionflow.server.api.dto.communication.response;
+
+import dev.lions.unionflow.server.api.enums.communication.MessagePriority;
+import dev.lions.unionflow.server.api.enums.communication.MessageStatus;
+import dev.lions.unionflow.server.api.enums.communication.MessageType;
+import lombok.Builder;
+
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.UUID;
+
+/**
+ * Response DTO pour Message
+ *
+ * @author UnionFlow Team
+ * @version 1.0
+ * @since 2026-03-16
+ */
+@Builder
+public record MessageResponse(
+    UUID id,
+    UUID conversationId,
+    UUID senderId,
+    String senderName,
+    String senderAvatar,
+    String content,
+    MessageType type,
+    MessageStatus status,
+    MessagePriority priority,
+    List<UUID> recipientIds,
+    List<String> recipientRoles,
+    UUID organisationId,
+    LocalDateTime createdAt,
+    LocalDateTime readAt,
+    List<String> attachments,
+    boolean isEdited,
+    LocalDateTime editedAt,
+    boolean isDeleted
+) {}

src/main/java/dev/lions/unionflow/server/api/enums/communication/ConversationType.java

@@ -0,0 +1,30 @@
+package dev.lions.unionflow.server.api.enums.communication;
+
+/**
+ * Type de conversation dans le système de messagerie
+ *
+ * @author UnionFlow Team
+ * @version 1.0
+ * @since 2026-03-16
+ */
+public enum ConversationType {
+    /**
+     * Conversation individuelle (1-1)
+     */
+    INDIVIDUAL,
+
+    /**
+     * Conversation de groupe
+     */
+    GROUP,
+
+    /**
+     * Canal broadcast (lecture seule pour la plupart)
+     */
+    BROADCAST,
+
+    /**
+     * Canal d'annonces organisation
+     */
+    ANNOUNCEMENT
+}

src/main/java/dev/lions/unionflow/server/api/enums/communication/MessagePriority.java

@@ -0,0 +1,25 @@
+package dev.lions.unionflow.server.api.enums.communication;
+
+/**
+ * Priorité du message
+ *
+ * @author UnionFlow Team
+ * @version 1.0
+ * @since 2026-03-16
+ */
+public enum MessagePriority {
+    /**
+     * Priorité normale
+     */
+    NORMAL,
+
+    /**
+     * Priorité élevée (important)
+     */
+    HIGH,
+
+    /**
+     * Priorité urgente (critique)
+     */
+    URGENT
+}

src/main/java/dev/lions/unionflow/server/api/enums/communication/MessageStatus.java

@@ -0,0 +1,30 @@
+package dev.lions.unionflow.server.api.enums.communication;
+
+/**
+ * Statut de lecture du message
+ *
+ * @author UnionFlow Team
+ * @version 1.0
+ * @since 2026-03-16
+ */
+public enum MessageStatus {
+    /**
+     * Envoyé mais non lu
+     */
+    SENT,
+
+    /**
+     * Livré (reçu par le serveur)
+     */
+    DELIVERED,
+
+    /**
+     * Lu par le destinataire
+     */
+    READ,
+
+    /**
+     * Échec d'envoi
+     */
+    FAILED
+}

src/main/java/dev/lions/unionflow/server/api/enums/communication/MessageType.java

@@ -0,0 +1,30 @@
+package dev.lions.unionflow.server.api.enums.communication;
+
+/**
+ * Type de message
+ *
+ * @author UnionFlow Team
+ * @version 1.0
+ * @since 2026-03-16
+ */
+public enum MessageType {
+    /**
+     * Message individuel (membre à membre)
+     */
+    INDIVIDUAL,
+
+    /**
+     * Broadcast organisation (OrgAdmin → tous)
+     */
+    BROADCAST,
+
+    /**
+     * Message ciblé par rôle (Moderator → groupe)
+     */
+    TARGETED,
+
+    /**
+     * Notification système
+     */
+    SYSTEM
+}