feat: export Markdown notes (ARQ/Redis) + backup/restore BDD — v0.5.2

- Volume data/ (bind mount ./data) remplace le volume uploads nommé
  data/notes/ → .md auto-générés, data/uploads/ → médias, data/backup/ → dumps
- Service Redis (redis:7-alpine) + worker ARQ (backend-worker)
- notes_markdown.py : frontmatter YAML + contenu + pièces jointes (liens relatifs)
  Nom : YYYY-MM-DD_slug-titre_shortid.md, rotation si titre modifié
- api/notes.py : publie export_note_markdown / remove_note_markdown sur Redis
  après chaque create / update / delete / add_attachment / delete_attachment
- api/admin.py : POST /backup, GET /backups, POST /restore/{filename} (pg_dump/pg_restore)
- Backend Dockerfile : postgresql-client ; requirements : arq==0.26.1
- ConfigPage : section "Base de données" avec sauvegarde + liste + restauration

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

backend/app/core/config.py

@@ -6,7 +6,9 @@ class Settings(BaseSettings):
     model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8")
 
     database_url: str = "postgresql+asyncpg://homehub:homehub@localhost:5432/homehub"
-    upload_dir: str = "/uploads"
+    upload_dir: str = "/data/uploads"
+    data_dir: str = "/data"
+    redis_url: str = "redis://redis:6379"
     cors_origins: str = "http://localhost:3000"
 
     @property
@@ -17,5 +19,13 @@ class Settings(BaseSettings):
     def upload_path(self) -> Path:
         return Path(self.upload_dir)
 
+    @property
+    def notes_md_path(self) -> Path:
+        return Path(self.data_dir) / "notes"
+
+    @property
+    def backup_path(self) -> Path:
+        return Path(self.data_dir) / "backup"
+
 
 settings = Settings()

backend/app/core/redis.py

@@ -0,0 +1,33 @@
+import logging
+from arq import create_pool
+from arq.connections import ArqRedis, RedisSettings
+from app.core.config import settings
+
+_pool: ArqRedis | None = None
+
+logger = logging.getLogger(__name__)
+
+
+async def init_redis() -> None:
+    global _pool
+    try:
+        _pool = await create_pool(RedisSettings.from_dsn(settings.redis_url))
+        logger.info("Redis pool initialisé")
+    except Exception as e:
+        logger.warning(f"Redis indisponible, export Markdown désactivé : {e}")
+
+
+async def close_redis() -> None:
+    global _pool
+    if _pool:
+        await _pool.close()
+        _pool = None
+
+
+async def enqueue(job_name: str, *args) -> None:
+    if _pool is None:
+        return
+    try:
+        await _pool.enqueue_job(job_name, *args)
+    except Exception as e:
+        logger.warning(f"Redis enqueue échoué ({job_name}) : {e}")