chore: déplacer apps.json vers v3/apps.json (format catalogue YunoHost API v3)

YunoHost construit l'URL du catalogue en ajoutant /v3/apps.json à l'URL
de base — le fichier doit donc être dans le sous-dossier v3/.

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

apps.json

@@ -1,17 +0,0 @@
-{
-  "apps": {
-    "backupmanager": {
-      "git": {
-        "url": "https://git.hansen.tl/YunoHost-Apps/backupmanager_ynh.git",
-        "branch": "main"
-      },
-      "state": "working",
-      "level": 7,
-      "manifest": {
-        "id": "backupmanager",
-        "name": "Backup Manager",
-        "version": "1.0~ynh1"
-      }
-    }
-  }
-}

v3/apps.json

@@ -0,0 +1,27 @@
+{
+  "apps": {
+    "backupmanager": {
+      "git": {
+        "url": "https://git.hansen.tl/YunoHost-Apps/backupmanager_ynh.git",
+        "branch": "main"
+      },
+      "state": "working",
+      "level": 7,
+      "maintained": true,
+      "antifeatures": [],
+      "category": "admin",
+      "subtags": [],
+      "manifest": {
+        "id": "backupmanager",
+        "name": "Backup Manager",
+        "version": "1.0~ynh1",
+        "description": {
+          "en": "Centralized backup manager for YunoHost",
+          "fr": "Gestionnaire de sauvegardes centralisé pour YunoHost"
+        }
+      }
+    }
+  },
+  "categories": [],
+  "antifeatures": {}
+}