feat(workspace,editor): creation dans le dossier courant + sync live du titre (sidebar/header)

- creation fichier/dossier a la racine du dossier courant ou d'un dossier cible (context-menu, boutons de survol) via createPage/showCreateFolderModal(parentId)
- instances de modeles en tant qu'enfant d'un dossier (parent_id) ; nom vide -> 'Untitled'
- sidebar de la librairie rafraichi apres delete/move/duplicate/rename (_syncSidebar)
- editeur: le titre se synchronise en direct dans le sidebar, le breadcrumb et l'onglet (pages et fichiers) et persiste via PUT /board/api/pages/{id}

app/routers/board.py

@@ -292,6 +292,12 @@ async def use_page_template(request: Request, template_id: int):
         body_ws = (body.get("workspace") or "").strip()
         if body_ws:
             ws_key = body_ws
+    # Optional target folder: instantiate the template as a child of it.
+    parent_id = body.get("parent_id")
+    try:
+        parent_id = int(parent_id) if parent_id not in (None, "", 0, "0") else None
+    except (TypeError, ValueError):
+        parent_id = None
     try:
         parsed_blocks = json.loads(blocks_json)
     except (json.JSONDecodeError, TypeError):
@@ -299,7 +305,12 @@ async def use_page_template(request: Request, template_id: int):
     _ensure_block_ids(parsed_blocks)
     blocks_json = json.dumps(parsed_blocks)
     with get_conn() as conn:
-        if ws_id is not None:
+        if parent_id is not None:
+            next_order = conn.execute(
+                "SELECT COALESCE(MAX(sort_order), -1) + 1 FROM pages WHERE parent_id=?",
+                (parent_id,),
+            ).fetchone()[0]
+        elif ws_id is not None:
             next_order = conn.execute(
                 "SELECT COALESCE(MAX(sort_order), -1) + 1 FROM pages WHERE workspace_id=? AND parent_id IS NULL",
                 (ws_id,),
@@ -310,9 +321,9 @@ async def use_page_template(request: Request, template_id: int):
                 (ws_key,),
             ).fetchone()[0]
         cur = conn.execute(
-            """INSERT INTO pages (workspace, workspace_id, title, content, content_format, parent_section, sort_order)
-               VALUES (?,?,?,?,?, 'Private', ?)""",
-            (ws_key, ws_id, title or name, blocks_json, "blocks", next_order),
+            """INSERT INTO pages (workspace, workspace_id, title, content, content_format, parent_section, parent_id, sort_order)
+               VALUES (?,?,?,?,?, 'Private', ?, ?)""",
+            (ws_key, ws_id, title or name, blocks_json, "blocks", parent_id, next_order),
         )
         conn.commit()
         page_id = cur.lastrowid