feat(project-management) : extract Projects/Tasks front into Nuxt module layer

Tranche 4 of LST-65. Companion to the backend module migration.

- Move pages (my-tasks, projects, projects/[id]/{index,groups,archives}),
  18 components (project + task), 10 services and 10 DTOs into
  frontend/modules/project-management/ (auto-detected layer).
- Rewrite explicit ~/services/* and ~/services/dto/* imports across 38
  consumers (admin tabs, mail modals, dashboard, mail page, layout) including
  the time-tracking module whose DTOs referenced project/task/task-tag.
- clients.ts and shared DTOs (client, user-data) stay at the root.
- Routes /my-tasks, /projects, /projects/:id(/groups|/archives) preserved;
  i18n stays global.

nuxt build passes; routes confirmed.

frontend/modules/project-management/components/TaskBookStackLinks.vue

@@ -0,0 +1,159 @@
+<template>
+    <div class="mt-5">
+        <p class="mb-2 text-sm font-medium text-neutral-700">{{ $t('bookstack.links.title') }}</p>
+
+        <!-- Search -->
+        <div class="relative">
+            <MalioInputText
+                v-model="searchQuery"
+                :placeholder="$t('bookstack.links.searchPlaceholder')"
+                input-class="w-full"
+            />
+
+            <!-- Dropdown results -->
+            <div
+                v-if="searchResults.length > 0"
+                class="absolute z-30 mt-1 w-full rounded-md border border-neutral-200 bg-white shadow-lg"
+            >
+                <button
+                    v-for="result in searchResults"
+                    :key="`${result.type}-${result.id}`"
+                    type="button"
+                    class="flex w-full items-center gap-2 px-3 py-2 text-left text-sm hover:bg-neutral-50"
+                    @click="handleAdd(result)"
+                >
+                    <Icon
+                        :name="result.type === 'page' ? 'mdi:file-document-outline' : 'mdi:book-outline'"
+                        size="16"
+                        class="shrink-0 text-neutral-400"
+                    />
+                    <span class="truncate">{{ result.name }}</span>
+                    <span class="ml-auto shrink-0 text-xs text-neutral-400">{{ result.type }}</span>
+                </button>
+            </div>
+
+            <p v-if="searchQuery.length >= 2 && !isSearching && searchResults.length === 0 && hasSearched" class="mt-1 text-xs text-neutral-400">
+                {{ $t('bookstack.links.noResults') }}
+            </p>
+        </div>
+
+        <!-- Linked documents -->
+        <div v-if="links.length > 0" class="mt-3 space-y-1">
+            <div
+                v-for="link in links"
+                :key="link.id"
+                class="flex items-center gap-2 rounded-md px-2 py-1.5 text-sm hover:bg-neutral-50"
+            >
+                <Icon
+                    :name="link.bookstackType === 'page' ? 'mdi:file-document-outline' : 'mdi:book-outline'"
+                    size="16"
+                    class="shrink-0 text-neutral-400"
+                />
+                <a
+                    :href="link.url"
+                    target="_blank"
+                    rel="noopener noreferrer"
+                    class="truncate text-primary-500 hover:underline"
+                >
+                    {{ link.title }}
+                </a>
+                <MalioButtonIcon
+                    icon="mdi:close"
+                    aria-label="Supprimer le lien"
+                    variant="ghost"
+                    icon-size="16"
+                    button-class="ml-auto shrink-0 text-neutral-300 hover:text-red-500"
+                    @click="handleRemove(link.id)"
+                />
+            </div>
+        </div>
+
+        <p v-else-if="!isLoading" class="mt-2 text-xs text-neutral-400">
+            {{ $t('bookstack.links.empty') }}
+        </p>
+    </div>
+</template>
+
+<script setup lang="ts">
+import type { BookStackLink, BookStackSearchResult } from '~/services/dto/bookstack'
+import { useBookStackService } from '~/services/bookstack'
+
+const props = defineProps<{
+    taskId: number
+}>()
+
+const { getLinks, addLink, removeLink, search } = useBookStackService()
+
+const links = ref<BookStackLink[]>([])
+const searchQuery = ref('')
+const searchResults = ref<BookStackSearchResult[]>([])
+const isLoading = ref(true)
+const isSearching = ref(false)
+const hasSearched = ref(false)
+
+let debounceTimer: ReturnType<typeof setTimeout> | null = null
+
+watch(searchQuery, (query) => {
+    if (debounceTimer) clearTimeout(debounceTimer)
+    hasSearched.value = false
+    searchResults.value = []
+
+    if (query.trim().length < 2) {
+        return
+    }
+
+    debounceTimer = setTimeout(async () => {
+        isSearching.value = true
+        try {
+            searchResults.value = await search(props.taskId, query.trim())
+        } catch {
+            searchResults.value = []
+        } finally {
+            isSearching.value = false
+            hasSearched.value = true
+        }
+    }, 300)
+})
+
+async function handleAdd(result: BookStackSearchResult) {
+    searchQuery.value = ''
+    searchResults.value = []
+    hasSearched.value = false
+
+    // Check if already linked
+    if (links.value.some(l => l.bookstackId === result.id && l.bookstackType === result.type)) {
+        return
+    }
+
+    try {
+        const created = await addLink(props.taskId, {
+            bookstackId: result.id,
+            bookstackType: result.type,
+            title: result.name,
+            url: result.url,
+        })
+        links.value.unshift(created)
+    } catch {
+        // Error handled by useApi toast
+    }
+}
+
+async function handleRemove(linkId: number) {
+    try {
+        await removeLink(props.taskId, linkId)
+        links.value = links.value.filter(l => l.id !== linkId)
+    } catch {
+        // Error handled by useApi toast
+    }
+}
+
+onMounted(async () => {
+    try {
+        links.value = await getLinks(props.taskId)
+    } catch {
+        // Error handled by useApi toast
+    } finally {
+        isLoading.value = false
+    }
+})
+</script>