feat: dossier personnel par utilisateur — vault home-<user> + registre de vaults persistant #194

- backend/user_home.py : ensure_user_home()/release_user_home() idempotents
  (mkdir, vault, watcher, octroi dans user.vaults), rappelés à la création
  d'un compte et au démarrage (migration + réparation + sweep des vaults
  home-* orphelins), dossier conservé à la suppression.
- backend/indexer.py : data/vaults.json, registre persistant des vaults
  ajoutés à la volée, fusionné par load_vault_config() — ils disparaissaient
  au premier reindex complet et au redémarrage. reload_single_vault remet
  vault_config[name] après remove_vault_from_index.
- backend/auth/router.py + routers/vaults.py : appels ensure/release +
  persistance à l'ajout/retrait d'un vault.
- docker-compose.yml : montage unique /NFS/OBSIDIAN_DOC/Home:/vaults/Home +
  OBSIGATE_HOME_ROOT (absente = fonctionnalité inactive).
- Tests : tests/test_user_home.py (12) + tests/test_auth_api.py::TestUserHome (2).

README.md

@@ -2,7 +2,7 @@
 
 **Ultra-light web gateway for your Obsidian vaults** — Access, browse, and search all your Obsidian notes from any device via a modern, responsive web interface.
 
-[![Version](https://img.shields.io/badge/Version-2.63.0-blue.svg)]()
+[![Version](https://img.shields.io/badge/Version-2.64.0-blue.svg)]()
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![Docker](https://img.shields.io/badge/Docker-Ready-blue.svg)](https://www.docker.com/)
 [![Python](https://img.shields.io/badge/Python-3.11+-green.svg)](https://www.python.org/)
@@ -238,6 +238,7 @@ Vaults are configured using pairs of `VAULT_N_NAME` / `VAULT_N_PATH` variables (
 | `VAULT_1_SCAN_ATTACHMENTS` | Enable image scanning on startup (optional, default: true) | `true` |
 | `VAULT_2_NAME` | Display name of the vault | `IT` |
 | `VAULT_2_PATH` | Path inside the container | `/vaults/Obsidian_IT` |
+| `OBSIGATE_HOME_ROOT` | Root folder for per-user home directories (one `home-<user>` vault per account). Unset = feature disabled. | `/vaults/Home` |
 
 **Naming rules:**
 - Use only letters, numbers, and hyphens
@@ -1151,8 +1152,8 @@ This project is licensed under the **MIT License** - see the [LICENSE](LICENSE)
 
 ## 📝 Changelog
 
-See [CHANGELOG.md](./CHANGELOG.md) for the complete version history (v1.0.0 → v2.63.0).
+See [CHANGELOG.md](./CHANGELOG.md) for the complete version history (v1.0.0 → v2.64.0).
 
 ---
 
-*Project: ObsiGate | Version: 2.63.0 | Last updated: September 2026*
+*Project: ObsiGate | Version: 2.64.0 | Last updated: September 2026*