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/services/notes_markdown.py

@@ -0,0 +1,79 @@
+import re
+import unicodedata
+from pathlib import Path
+
+from app.core.config import settings
+from app.models.notes import NoteItem
+
+
+def _slugify(text: str, max_len: int = 50) -> str:
+    text = unicodedata.normalize("NFD", text)
+    text = "".join(c for c in text if unicodedata.category(c) != "Mn")
+    text = text.lower()
+    text = re.sub(r"[^\w\s-]", "", text)
+    text = re.sub(r"[\s_-]+", "-", text)
+    return text.strip("-")[:max_len]
+
+
+def _note_filename(note: NoteItem) -> str:
+    date = note.created_at.strftime("%Y-%m-%d")
+    raw = note.title or note.content[:40]
+    slug = _slugify(raw) or "sans-titre"
+    short_id = str(note.id)[:8]
+    return f"{date}_{slug}_{short_id}.md"
+
+
+def _render(note: NoteItem) -> str:
+    lines = ["---"]
+    lines.append(f"id: {note.id}")
+    if note.title:
+        lines.append(f'title: "{note.title}"')
+    if note.category:
+        lines.append(f"category: {note.category}")
+    if note.tags:
+        tags_str = ", ".join(f'"{t}"' for t in note.tags)
+        lines.append(f"tags: [{tags_str}]")
+    lines.append(f"created_at: {note.created_at.isoformat()}")
+    if note.gps_lat is not None and note.gps_lon is not None:
+        lines.append(f'gps: "{note.gps_lat}, {note.gps_lon}"')
+    lines.append("---")
+    lines.append("")
+    lines.append(note.content)
+
+    images = [a for a in note.attachments if a.file_type == "image" and a.file_path]
+    audios = [a for a in note.attachments if a.file_type == "audio" and a.file_path]
+
+    if images or audios:
+        lines.append("")
+        lines.append("## Pièces jointes")
+        lines.append("")
+        for att in images:
+            # file_path est relatif à UPLOAD_DIR, ex: "images/originals/uuid.webp"
+            rel = f"../uploads/{att.file_path}"
+            name = att.original_name or "image"
+            lines.append(f"![{name}]({rel})")
+        for att in audios:
+            rel = f"../uploads/{att.file_path}"
+            name = att.original_name or "audio"
+            lines.append(f"[{name}]({rel})")
+
+    return "\n".join(lines) + "\n"
+
+
+def save_note_markdown(note: NoteItem) -> None:
+    notes_dir = settings.notes_md_path
+    notes_dir.mkdir(parents=True, exist_ok=True)
+    short_id = str(note.id)[:8]
+    # Supprime l'ancienne version (titre peut avoir changé)
+    for old in notes_dir.glob(f"*_{short_id}.md"):
+        old.unlink()
+    (notes_dir / _note_filename(note)).write_text(_render(note), encoding="utf-8")
+
+
+def delete_note_markdown(note_id: str) -> None:
+    notes_dir = settings.notes_md_path
+    if not notes_dir.exists():
+        return
+    short_id = note_id[:8]
+    for f in notes_dir.glob(f"*_{short_id}.md"):
+        f.unlink()