Sprint 2 : moteur de documents + sanctuaire

Backend:
- CRUD complet documents/items/versions (update, delete, accept, reject, reorder)
- Service IPFS (upload/retrieve/pin via kubo HTTP API)
- Service sanctuaire : pipeline SHA-256 + IPFS + on-chain (system.remark)
- Verification integrite des entrees sanctuaire
- Recherche par reference (document -> entrees sanctuaire)
- Serialisation deterministe des documents pour archivage
- 14 tests unitaires supplementaires (document service)

Frontend:
- 9 composants : StatusBadge, MarkdownRenderer, DiffView, ItemCard,
  ItemVersionDiff, DocumentList, SanctuaryEntry, IPFSLink, ChainAnchor
- Page detail item avec historique des versions et diff
- Page detail sanctuaire avec verification integrite
- Modal de creation de document + proposition de version
- Archivage document vers sanctuaire depuis la page detail

Documentation:
- API reference mise a jour (9 nouveaux endpoints)
- Guides utilisateur documents et sanctuaire enrichis

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

frontend/app/components/common/DiffView.vue

@@ -0,0 +1,51 @@
+<script setup lang="ts">
+const props = defineProps<{
+  diff: string
+}>()
+
+interface DiffLine {
+  text: string
+  type: 'added' | 'removed' | 'header' | 'context'
+}
+
+const parsedLines = computed((): DiffLine[] => {
+  if (!props.diff) return []
+
+  return props.diff.split('\n').map((line) => {
+    if (line.startsWith('@@')) {
+      return { text: line, type: 'header' as const }
+    }
+    if (line.startsWith('+')) {
+      return { text: line, type: 'added' as const }
+    }
+    if (line.startsWith('-')) {
+      return { text: line, type: 'removed' as const }
+    }
+    return { text: line, type: 'context' as const }
+  })
+})
+
+function lineClass(type: DiffLine['type']): string {
+  switch (type) {
+    case 'added':
+      return 'bg-green-50 dark:bg-green-900/20 text-green-800 dark:text-green-300'
+    case 'removed':
+      return 'bg-red-50 dark:bg-red-900/20 text-red-800 dark:text-red-300'
+    case 'header':
+      return 'bg-blue-50 dark:bg-blue-900/20 text-blue-700 dark:text-blue-300 font-semibold'
+    default:
+      return 'text-gray-700 dark:text-gray-300'
+  }
+}
+</script>
+
+<template>
+  <div class="border border-gray-200 dark:border-gray-700 rounded-lg overflow-hidden">
+    <pre class="text-xs font-mono leading-relaxed overflow-x-auto"><template
+      v-for="(line, index) in parsedLines"
+      :key="index"
+    ><div
+        :class="['px-4 py-0.5', lineClass(line.type)]"
+      >{{ line.text }}</div></template></pre>
+  </div>
+</template>