refactor(i18n) : replace hardcoded French strings with i18n keys

Replace 30+ hardcoded strings across 15 components with $t() calls.
Added keys for common actions, drawers titles, empty states, and modals.

Ticket: T-020

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/components/time-tracking/TimeEntryBlock.vue

@@ -21,7 +21,7 @@
             <!-- Full display: title + project + type dot + duration -->
             <template v-if="sizeLevel >= 3">
                 <div class="flex items-center gap-1">
-                    <div class="font-semibold truncate">{{ entry.title || 'Sans titre' }}</div>
+                    <div class="font-semibold truncate">{{ entry.title || $t('common.untitled') }}</div>
                     <span class="ml-auto shrink-0 text-[10px] tabular-nums opacity-80">{{ duration }}</span>
                 </div>
                 <div v-if="entry.project" class="truncate text-[10px] opacity-80">{{ entry.project.name }}</div>
@@ -39,13 +39,13 @@
 
             <!-- Medium: title + duration -->
             <template v-else-if="sizeLevel === 2">
-                <div class="font-semibold truncate">{{ entry.title || 'Sans titre' }}</div>
+                <div class="font-semibold truncate">{{ entry.title || $t('common.untitled') }}</div>
                 <div class="text-[10px] tabular-nums opacity-80">{{ duration }}</div>
             </template>
 
             <!-- Small: title only -->
             <template v-else-if="sizeLevel === 1">
-                <div class="font-semibold truncate text-[10px] leading-tight">{{ entry.title || 'Sans titre' }}</div>
+                <div class="font-semibold truncate text-[10px] leading-tight">{{ entry.title || $t('common.untitled') }}</div>
             </template>
 
             <!-- Tiny: just a colored bar, no text -->

frontend/components/time-tracking/TimeEntryDrawer.vue

@@ -1,5 +1,5 @@
 <template>
-    <AppDrawer v-model="isOpen" :title="isEditing ? 'Modifier un temps' : 'Ajouter une Activité'">
+    <AppDrawer v-model="isOpen" :title="isEditing ? $t('timeEntries.editEntry') : $t('timeEntries.addEntry')">
         <form class="space-y-4" @submit.prevent="onSubmit">
             <div>
                 <label class="mb-1 block text-sm font-semibold text-neutral-700">Titre</label>
@@ -117,7 +117,7 @@
 </template>
 
 <script setup lang="ts">
-import type { TimeEntry } from '~/services/dto/time-entry'
+import type { TimeEntry, TimeEntryWrite } from '~/services/dto/time-entry'
 import type { UserData } from '~/services/dto/user-data'
 import type { Project } from '~/services/dto/project'
 import type { TaskTag } from '~/services/dto/task-tag'
@@ -257,7 +257,7 @@ async function onSubmit() {
     if (isEditing.value && props.entry) {
         await update(props.entry.id, payload)
     } else {
-        await create(payload as any)
+        await create(payload as TimeEntryWrite)
     }
 
     emit('saved')

frontend/components/time-tracking/TimeEntryList.vue

@@ -1,7 +1,7 @@
 <template>
     <div class="space-y-2">
         <div v-if="entries.length === 0" class="rounded-lg border border-neutral-200 bg-neutral-50 py-12 text-center text-sm text-neutral-400">
-            Aucune activité pour cette période
+            {{ $t('timeEntries.noEntries') }}
         </div>
 
         <div
@@ -20,7 +20,7 @@
             <div class="min-w-0 flex-1">
                 <div class="flex items-center gap-2">
                     <span class="truncate text-sm font-semibold text-neutral-900">
-                        {{ entry.title || 'Sans titre' }}
+                        {{ entry.title || $t('common.untitled') }}
                     </span>
                     <span
                         v-for="tag in entry.tags"
@@ -56,7 +56,7 @@
             <!-- Delete action -->
             <button
                 class="shrink-0 rounded-md p-1.5 text-neutral-300 opacity-0 transition hover:bg-red-50 hover:text-red-500 group-hover:opacity-100"
-                title="Supprimer"
+                :title="$t('common.delete')"
                 @click.stop="emit('deleteEntry', entry)"
             >
                 <Icon name="mdi:delete-outline" size="18" />

frontend/components/time-tracking/TimeTrackingCalendar.vue

@@ -99,7 +99,7 @@
                             :style="{ backgroundColor: entry.project?.color ?? '#94a3b8' }"
                         />
                         <div class="min-w-0">
-                            <div class="truncate text-xs font-medium text-neutral-800">{{ entry.title || 'Sans titre' }}</div>
+                            <div class="truncate text-xs font-medium text-neutral-800">{{ entry.title || $t('common.untitled') }}</div>
                             <div class="text-[10px] text-neutral-500">
                                 {{ formatTime(entry.startedAt) }} – {{ entry.stoppedAt ? formatTime(entry.stoppedAt) : '...' }}
                             </div>
@@ -141,6 +141,8 @@
 <script setup lang="ts">
 import type { TimeEntry } from '~/services/dto/time-entry'
 
+const { t } = useI18n()
+
 const props = defineProps<{
     entries: TimeEntry[]
     startDate: Date
@@ -459,7 +461,7 @@ function onMoveStart(payload: { entry: TimeEntry; offsetY: number }, sourceDayIn
     dragState.value = {
         entryId: entry.id,
         entry,
-        title: entry.title || 'Sans titre',
+        title: entry.title || t('common.untitled'),
         color: entry.project?.color ?? '#94a3b8',
         durationMinutes,
         ghostHeightPx: Math.max((durationMinutes / 60) * hourHeight, 20),