feat : add User CRUD with admin management

Add User API operations (GET, POST, PATCH, DELETE) with password
hashing processor, frontend service, drawer and admin tab.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/components/AdminUserTab.vue

@@ -0,0 +1,106 @@
+<template>
+    <div>
+        <div class="flex items-center justify-between">
+            <h2 class="text-lg font-bold text-neutral-900">Utilisateurs</h2>
+            <button
+                class="rounded-md bg-primary-500 px-4 py-2 text-sm font-semibold text-white hover:bg-secondary-500"
+                @click="openCreate"
+            >
+                + Ajouter un utilisateur
+            </button>
+        </div>
+
+        <div class="mt-6 overflow-x-auto rounded-lg border border-neutral-200">
+            <table class="w-full text-left text-sm">
+                <thead class="border-b border-neutral-200 bg-neutral-50">
+                    <tr>
+                        <th class="px-4 py-3 font-semibold text-neutral-700">Nom d'utilisateur</th>
+                        <th class="px-4 py-3 font-semibold text-neutral-700">Rôles</th>
+                        <th class="px-4 py-3 font-semibold text-neutral-700">Actions</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    <tr
+                        v-for="item in items"
+                        :key="item.id"
+                        class="cursor-pointer border-b border-neutral-100 hover:bg-neutral-50"
+                        @click="openEdit(item)"
+                    >
+                        <td class="px-4 py-3 font-semibold text-primary-500">{{ item.username }}</td>
+                        <td class="px-4 py-3">
+                            <span
+                                v-for="role in item.roles"
+                                :key="role"
+                                class="mr-1 rounded-full bg-neutral-200 px-2 py-0.5 text-xs font-semibold text-neutral-700"
+                            >
+                                {{ role }}
+                            </span>
+                        </td>
+                        <td class="px-4 py-3">
+                            <button
+                                class="text-red-500 hover:text-red-700"
+                                @click.stop="handleDelete(item.id)"
+                            >
+                                <Icon name="mdi:delete-outline" size="20" />
+                            </button>
+                        </td>
+                    </tr>
+                    <tr v-if="items.length === 0 && !isLoading">
+                        <td colspan="3" class="px-4 py-8 text-center text-neutral-400">
+                            Aucun utilisateur trouvé.
+                        </td>
+                    </tr>
+                </tbody>
+            </table>
+        </div>
+
+        <UserDrawer
+            v-model="drawerOpen"
+            :item="selectedItem"
+            @saved="onSaved"
+        />
+    </div>
+</template>
+
+<script setup lang="ts">
+import type { UserData } from '~/services/dto/user-data'
+import { useUserService } from '~/services/users'
+
+const { getAll, remove } = useUserService()
+const items = ref<UserData[]>([])
+const isLoading = ref(true)
+const drawerOpen = ref(false)
+const selectedItem = ref<UserData | null>(null)
+
+async function loadItems() {
+    isLoading.value = true
+    try {
+        items.value = await getAll()
+    } finally {
+        isLoading.value = false
+    }
+}
+
+function openCreate() {
+    selectedItem.value = null
+    drawerOpen.value = true
+}
+
+function openEdit(item: UserData) {
+    selectedItem.value = item
+    drawerOpen.value = true
+}
+
+async function handleDelete(id: number) {
+    await remove(id)
+    await loadItems()
+}
+
+async function onSaved() {
+    await loadItems()
+}
+
+onMounted(() => {
+    loadItems()
+})
+</script>