fix(import): add missing league/csv dependency

ImportClientsAction uses League\Csv\Reader but the package was never
added to composer.json/lock, so it worked locally (already present
from a prior require elsewhere?) but was absent from the production
vendor/ build, causing a fatal "class not found" on every CSV import.

backend/composer.json

@@ -9,7 +9,8 @@
         "guzzlehttp/guzzle": "^7.2",
         "laravel/framework": "^10.10",
         "laravel/sanctum": "^3.3",
-        "laravel/tinker": "^2.8"
+        "laravel/tinker": "^2.8",
+        "league/csv": "^9.28"
     },
     "require-dev": {
         "fakerphp/faker": "^1.9.1",

backend/composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "99f05eafe03969ab53fabeb534bd2444",
+    "content-hash": "8bd73c76620cdf1a83b112238c5450c1",
     "packages": [
         {
             "name": "brick/math",
@@ -1706,6 +1706,97 @@
             ],
             "time": "2022-12-11T20:36:23+00:00"
         },
+        {
+            "name": "league/csv",
+            "version": "9.28.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/thephpleague/csv.git",
+                "reference": "6582ace29ae09ba5b07049d40ea13eb19c8b5073"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/thephpleague/csv/zipball/6582ace29ae09ba5b07049d40ea13eb19c8b5073",
+                "reference": "6582ace29ae09ba5b07049d40ea13eb19c8b5073",
+                "shasum": ""
+            },
+            "require": {
+                "ext-filter": "*",
+                "php": "^8.1.2"
+            },
+            "require-dev": {
+                "ext-dom": "*",
+                "ext-xdebug": "*",
+                "friendsofphp/php-cs-fixer": "^3.92.3",
+                "phpbench/phpbench": "^1.4.3",
+                "phpstan/phpstan": "^1.12.32",
+                "phpstan/phpstan-deprecation-rules": "^1.2.1",
+                "phpstan/phpstan-phpunit": "^1.4.2",
+                "phpstan/phpstan-strict-rules": "^1.6.2",
+                "phpunit/phpunit": "^10.5.16 || ^11.5.22 || ^12.5.4",
+                "symfony/var-dumper": "^6.4.8 || ^7.4.0 || ^8.0"
+            },
+            "suggest": {
+                "ext-dom": "Required to use the XMLConverter and the HTMLConverter classes",
+                "ext-iconv": "Needed to ease transcoding CSV using iconv stream filters",
+                "ext-mbstring": "Needed to ease transcoding CSV using mb stream filters",
+                "ext-mysqli": "Requiered to use the package with the MySQLi extension",
+                "ext-pdo": "Required to use the package with the PDO extension",
+                "ext-pgsql": "Requiered to use the package with the PgSQL extension",
+                "ext-sqlite3": "Required to use the package with the SQLite3 extension"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "9.x-dev"
+                }
+            },
+            "autoload": {
+                "files": [
+                    "src/functions_include.php"
+                ],
+                "psr-4": {
+                    "League\\Csv\\": "src"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Ignace Nyamagana Butera",
+                    "email": "nyamsprod@gmail.com",
+                    "homepage": "https://github.com/nyamsprod/",
+                    "role": "Developer"
+                }
+            ],
+            "description": "CSV data manipulation made easy in PHP",
+            "homepage": "https://csv.thephpleague.com",
+            "keywords": [
+                "convert",
+                "csv",
+                "export",
+                "filter",
+                "import",
+                "read",
+                "transform",
+                "write"
+            ],
+            "support": {
+                "docs": "https://csv.thephpleague.com",
+                "issues": "https://github.com/thephpleague/csv/issues",
+                "rss": "https://github.com/thephpleague/csv/releases.atom",
+                "source": "https://github.com/thephpleague/csv"
+            },
+            "funding": [
+                {
+                    "url": "https://github.com/sponsors/nyamsprod",
+                    "type": "github"
+                }
+            ],
+            "time": "2025-12-27T15:18:42+00:00"
+        },
         {
             "name": "league/flysystem",
             "version": "3.35.2",