feat: complete Epic 0 — foundation migration & infrastructure setup

Stories 0.2-0.5: rename folders→declarations (backend+frontend), configure
Redis for cache/queue/sessions, add foundation database migrations
(permissions, archived_at), replace DeclarationStatus enum with architecture
lifecycle values, create DeclarationObserver for status transition validation
and auto-archive, fix controller status transitions to respect observer rules.

93 tests pass (240 assertions).

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

resources/js/components/clients/DeclarationCalendar.vue

@@ -0,0 +1,142 @@
+<script setup lang="ts">
+import { ChevronLeft, ChevronRight } from 'lucide-vue-next';
+import { computed, ref } from 'vue';
+import { Button } from '@/components/ui/button';
+
+type Declaration = {
+    id: number;
+    due_date: string | null;
+};
+
+type Props = {
+    declarations: Declaration[];
+};
+
+const props = defineProps<Props>();
+
+const monthNames = [
+    'Janvier',
+    'Février',
+    'Mars',
+    'Avril',
+    'Mai',
+    'Juin',
+    'Juillet',
+    'Août',
+    'Septembre',
+    'Octobre',
+    'Novembre',
+    'Décembre',
+];
+const dayNames = ['Lun', 'Mar', 'Mer', 'Jeu', 'Ven', 'Sam', 'Dim'];
+
+const current = ref(new Date());
+
+const monthLabel = computed(
+    () =>
+        `${monthNames[current.value.getMonth()]} ${current.value.getFullYear()}`,
+);
+
+const datesWithDeclarations = computed(() => {
+    const set = new Set<string>();
+    props.declarations.forEach((f) => {
+        if (f.due_date) set.add(f.due_date);
+    });
+    return set;
+});
+
+const declarationsByDate = computed(() => {
+    const map = new Map<string, number>();
+    props.declarations.forEach((f) => {
+        if (f.due_date) {
+            map.set(f.due_date, (map.get(f.due_date) ?? 0) + 1);
+        }
+    });
+    return map;
+});
+
+const calendarDays = computed(() => {
+    const year = current.value.getFullYear();
+    const month = current.value.getMonth();
+    const first = new Date(year, month, 1);
+    const last = new Date(year, month + 1, 0);
+    const startDay = (first.getDay() + 6) % 7;
+    const daysInMonth = last.getDate();
+
+    const days: Array<{
+        date: Date | null;
+        dateStr: string | null;
+        count: number;
+    }> = [];
+
+    for (let i = 0; i < startDay; i++) {
+        days.push({ date: null, dateStr: null, count: 0 });
+    }
+    for (let d = 1; d <= daysInMonth; d++) {
+        const date = new Date(year, month, d);
+        const dateStr = `${year}-${String(month + 1).padStart(2, '0')}-${String(d).padStart(2, '0')}`;
+        days.push({
+            date,
+            dateStr,
+            count: declarationsByDate.value.get(dateStr) ?? 0,
+        });
+    }
+    return days;
+});
+
+function prevMonth() {
+    current.value = new Date(
+        current.value.getFullYear(),
+        current.value.getMonth() - 1,
+    );
+}
+
+function nextMonth() {
+    current.value = new Date(
+        current.value.getFullYear(),
+        current.value.getMonth() + 1,
+    );
+}
+</script>
+
+<template>
+    <div class="rounded-xl border border-sidebar-border/70 bg-card p-4">
+        <div class="mb-4 flex items-center justify-between">
+            <Button variant="ghost" size="icon" @click="prevMonth">
+                <ChevronLeft class="size-4" />
+            </Button>
+            <span class="text-sm font-medium">{{ monthLabel }}</span>
+            <Button variant="ghost" size="icon" @click="nextMonth">
+                <ChevronRight class="size-4" />
+            </Button>
+        </div>
+        <div class="grid grid-cols-7 gap-1 text-center text-xs">
+            <div
+                v-for="day in dayNames"
+                :key="day"
+                class="py-1 font-medium text-muted-foreground"
+            >
+                {{ day }}
+            </div>
+            <div
+                v-for="(cell, i) in calendarDays"
+                :key="i"
+                class="flex min-h-8 flex-col items-center justify-center rounded-md py-1"
+                :class="[
+                    !cell.date
+                        ? 'invisible'
+                        : cell.count > 0
+                          ? 'bg-primary/15 font-medium'
+                          : 'text-muted-foreground hover:bg-muted/50',
+                ]"
+            >
+                <template v-if="cell.date">
+                    {{ cell.date.getDate() }}
+                    <span v-if="cell.count > 0" class="mt-0.5 text-[10px]">
+                        {{ cell.count }} décl.
+                    </span>
+                </template>
+            </div>
+        </div>
+    </div>
+</template>