fix: vault home recursive + backup viewer fixes + AI status at startup

- Vault home (#12): recursive file listing (rglob), rel_dir in metadata,
  'recursif' badge, updated roadmap description
- Backup viewer: fix close button (inline onclick + event delegation
  fallback for text nodes), improve error messages
- Backup API: remove response_model to prevent Pydantic 500 errors,
  add try/except + logging on backups/diff/restore endpoints,
  per-entry error handling in _list_backup_files,
  encoding safety (errors='replace') on read_text
- AI status: call /api/ai/status at startup in _initAIStatus
  instead of waiting for user click on sync badge

frontend/js/vaulthome.js

@@ -2,7 +2,9 @@
  * Vault Home Page module for ObsiGate.
  *
  * When a specific vault is selected (not "All"), replaces the dashboard
- * with a file listing sorted by modification time (newest first).
+ * with a recursive file listing sorted by modification time (newest first).
+ * Files from the selected directory AND all its subdirectories are shown
+ * with their relative path displayed in the metadata line.
  * The listing updates automatically when browsing into subdirectories.
  *
  * The visual style mirrors the search results (.search-result-item) for
@@ -184,7 +186,7 @@ function buildBreadcrumbHTML(parentEl, vaultName, dirPath) {
 
 async function loadAndRender(vaultName, dirPath, container) {
   try {
-    const url = `/api/vault/${encodeURIComponent(vaultName)}/files?dir=${encodeURIComponent(dirPath)}&limit=200`;
+    const url = `/api/vault/${encodeURIComponent(vaultName)}/files?dir=${encodeURIComponent(dirPath)}&limit=200&recursive=true`;
     const data = await api(url);
 
     if (!data.files || data.files.length === 0) {
@@ -204,7 +206,15 @@ async function loadAndRender(vaultName, dirPath, container) {
     ]);
     header.appendChild(count);
 
-    // Sort dropdown (already sorted by mtime from backend)
+    // Recursive indicator
+    if (data.recursive) {
+      const recursiveBadge = el('span', { class: 'vault-home-recursive-badge' }, [
+        document.createTextNode('récursif'),
+      ]);
+      header.appendChild(recursiveBadge);
+    }
+
+    // Directory label
     const dirLabel = dirPath ? `/${dirPath}` : ' (racine)';
     const dirInfo = el('span', { class: 'vault-home-dir-info' }, [
       document.createTextNode(dirLabel),
@@ -233,8 +243,16 @@ async function loadAndRender(vaultName, dirPath, container) {
         hour: '2-digit', minute: '2-digit',
       });
 
+      // Build metadata line: rel_dir (if any) + date + size
+      const metaParts = [];
+      if (f.rel_dir) {
+        metaParts.push(f.rel_dir + '/');
+      }
+      metaParts.push(dateStr);
+      metaParts.push(formatSize(f.size));
+
       const metaDiv = el('div', { class: 'search-result-vault' }, [
-        document.createTextNode(`${dateStr}  ·  ${formatSize(f.size)}`),
+        document.createTextNode(metaParts.join('  ·  ')),
       ]);
 
       const item = el('div', {