feat(backend): Ajout complet des fonctionnalités Chat, Social, Story et Notifications

Implémentation complète de toutes les fonctionnalités backend :

## Nouvelles Fonctionnalités

### Chat (Messagerie Instantanée)
- Entities : Conversation, Message
- DTOs : ConversationResponseDTO, MessageResponseDTO, SendMessageRequestDTO
- Resources : MessageResource (endpoints REST)
- Services : MessageService (logique métier)
- Repositories : ConversationRepository, MessageRepository
- WebSocket : ChatWebSocket (temps réel)

### Social (Publications Sociales)
- Entities : SocialPost, SocialComment, SocialLike
- DTOs : SocialPostResponseDTO, CreateSocialPostRequestDTO
- Resources : SocialPostResource
- Services : SocialPostService
- Repositories : SocialPostRepository

### Story (Stories temporaires)
- Entities : Story, StoryView
- DTOs : StoryResponseDTO, CreateStoryRequestDTO
- Resources : StoryResource
- Services : StoryService
- Repositories : StoryRepository

### Notifications (Temps Réel)
- Entities : Notification
- DTOs : NotificationResponseDTO
- Resources : NotificationResource
- Services : NotificationService, PresenceService
- Repositories : NotificationRepository
- WebSocket : NotificationWebSocket (temps réel)

## Améliorations

### Users & Friendship
- Mise à jour UserResponseDTO avec nouveaux champs
- Amélioration FriendshipResource avec séparation demandes envoyées/reçues
- FriendSuggestionResponseDTO pour suggestions d'amis
- Optimisations dans UsersService et FriendshipService

### Events
- Améliorations EventsResource et EventService
- Optimisations EventsRepository

### Configuration
- Mise à jour application.properties
- Configuration docker-compose.yml
- Dockerfile pour développement

## Fichiers Modifiés
- .dockerignore, .gitignore
- README.md
- docker-compose.yml
- Configuration Maven wrapper

mvnw.cmd

@@ -18,7 +18,7 @@
 @REM ----------------------------------------------------------------------------
 
 @REM ----------------------------------------------------------------------------
-@REM Apache Maven Wrapper startup batch script, version 3.2.0
+@REM Apache Maven Wrapper startup batch script, version 3.3.2
 @REM
 @REM Required ENV vars:
 @REM JAVA_HOME - location of a JDK home dir
@@ -59,22 +59,22 @@ set ERROR_CODE=0
 @REM ==== START VALIDATION ====
 if not "%JAVA_HOME%" == "" goto OkJHome
 
-echo.
+echo. >&2
 echo Error: JAVA_HOME not found in your environment. >&2
 echo Please set the JAVA_HOME variable in your environment to match the >&2
 echo location of your Java installation. >&2
-echo.
+echo. >&2
 goto error
 
 :OkJHome
 if exist "%JAVA_HOME%\bin\java.exe" goto init
 
-echo.
+echo. >&2
 echo Error: JAVA_HOME is set to an invalid directory. >&2
 echo JAVA_HOME = "%JAVA_HOME%" >&2
 echo Please set the JAVA_HOME variable in your environment to match the >&2
 echo location of your Java installation. >&2
-echo.
+echo. >&2
 goto error
 
 @REM ==== END VALIDATION ====
@@ -119,7 +119,7 @@ SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
 set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
 set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
 
-set WRAPPER_URL="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar"
+set WRAPPER_URL="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.3.2/maven-wrapper-3.3.2.jar"
 
 FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
     IF "%%A"=="wrapperUrl" SET WRAPPER_URL=%%B
@@ -133,7 +133,7 @@ if exist %WRAPPER_JAR% (
     )
 ) else (
     if not "%MVNW_REPOURL%" == "" (
-        SET WRAPPER_URL="%MVNW_REPOURL%/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar"
+        SET WRAPPER_URL="%MVNW_REPOURL%/org/apache/maven/wrapper/maven-wrapper/3.3.2/maven-wrapper-3.3.2.jar"
     )
     if "%MVNW_VERBOSE%" == "true" (
         echo Couldn't find %WRAPPER_JAR%, downloading it ...
@@ -160,11 +160,12 @@ FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapp
 )
 IF NOT %WRAPPER_SHA_256_SUM%=="" (
     powershell -Command "&{"^
+       "Import-Module $PSHOME\Modules\Microsoft.PowerShell.Utility -Function Get-FileHash;"^
        "$hash = (Get-FileHash \"%WRAPPER_JAR%\" -Algorithm SHA256).Hash.ToLower();"^
        "If('%WRAPPER_SHA_256_SUM%' -ne $hash){"^
-       "  Write-Output 'Error: Failed to validate Maven wrapper SHA-256, your Maven wrapper might be compromised.';"^
-       "  Write-Output 'Investigate or delete %WRAPPER_JAR% to attempt a clean download.';"^
-       "  Write-Output 'If you updated your Maven version, you need to update the specified wrapperSha256Sum property.';"^
+       "  Write-Error 'Error: Failed to validate Maven wrapper SHA-256, your Maven wrapper might be compromised.';"^
+       "  Write-Error 'Investigate or delete %WRAPPER_JAR% to attempt a clean download.';"^
+       "  Write-Error 'If you updated your Maven version, you need to update the specified wrapperSha256Sum property.';"^
        "  exit 1;"^
        "}"^
        "}"