feat: sidebar tree navigation — toggle chevrons + drag & drop

- Add sort_order column to pages table for drag & drop reordering
- Rewrite _sidebar_data with recursive _build_page_tree for nested hierarchy
- Add tree toggle buttons (▶ collapsed / ▼ expanded) on parent items
- Alpine.js expandedNodes state with toggleTreeNode() for expand/collapse
- Jinja2 recursive macro render_tree_item for proper nesting + indentation
- SortableJS integration on .sidebar-items for drag & drop repositioning
- New PUT /board/api/pages/{id}/move API for persisting moves
- Auto-set sort_order on page creation (max+1 for same parent)
- CSS: .tree-toggle, .tree-toggle-placeholder, grab cursor on page-icon
- 28/28 tests pass, all endpoints healthy

app/routers/board.py

@@ -115,6 +115,31 @@ def _map_issue_to_card(issue: dict, owner: str = "", repo: str = "") -> dict:
     }
 
 
+def _build_page_tree(conn, parent_id: int | None, ws_key: str, depth: int = 0, max_depth: int = 3) -> list[dict]:
+    """Build nested page tree recursively. max_depth prevents infinite recursion."""
+    if depth >= max_depth:
+        return []
+    rows = conn.execute(
+        "SELECT id, title, updated_at FROM pages WHERE workspace=? AND parent_id IS ? ORDER BY sort_order ASC, updated_at DESC",
+        (ws_key, parent_id),
+    ).fetchall()
+    items = []
+    for row in rows:
+        children = _build_page_tree(conn, row["id"], ws_key, depth + 1, max_depth)
+        items.append({
+            "id": f"page/{row['id']}",
+            "db_id": row["id"],
+            "name": row["title"],
+            "icon": "📄",
+            "url": f"/pages/{row['id']}",
+            "active": False,
+            "depth": depth,
+            "has_children": len(children) > 0,
+            "children": children,
+        })
+    return items
+
+
 def _sidebar_data(request: Request, owner: str = "", repo: str = "") -> dict:
     user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
     ws_name = user.get("login", "Bruno") if user else "Bruno"
@@ -134,32 +159,19 @@ def _sidebar_data(request: Request, owner: str = "", repo: str = "") -> dict:
                 "name": label, "icon": "📁" if first else "·",
                 "url": f"/board/{owner}/{repo}?view={view}",
                 "active": active, "indent": indent,
+                "depth": indent, "has_children": False, "children": [],
             })
             first = False
-    # Load pages for this project workspace
+    # Load pages as nested tree for this project workspace
     with get_conn() as conn:
-        pages = conn.execute(
-            "SELECT id, title, parent_id, updated_at FROM pages WHERE workspace=? AND parent_id IS NULL ORDER BY updated_at DESC LIMIT 10",
-            (ws_key,),
-        ).fetchall()
-        for p in pages:
-            recent.append({
-                "id": f"page/{p['id']}", "name": p["title"], "icon": "📄",
-                "url": f"/pages/{p['id']}", "active": False, "indent": 0,
-            })
-            # Load sub-pages
-            subs = conn.execute(
-                "SELECT id, title FROM pages WHERE parent_id=? ORDER BY updated_at DESC",
-                (p["id"],),
-            ).fetchall()
-            for sp in subs:
-                recent.append({
-                    "id": f"page/{sp['id']}", "name": sp["title"], "icon": "·",
-                    "url": f"/pages/{sp['id']}", "active": False, "indent": 1,
-                })
+        tree_pages = _build_page_tree(conn, None, ws_key)
+        for p in tree_pages:
+            recent.append(p)
+    # Private pages: same as recent but filtered for page/ items (non-board views)
+    private_items = [r for r in recent if r.get("active") or r["id"].startswith("page/")]
     return {"workspace_name": ws_name, "workspace_initial": ws_name[0].upper() if ws_name else "B",
             "current_page": repo or "Dashboard", "last_edited": "now",
-            "recent_pages": recent, "private_pages": [r for r in recent if r.get("active") or r["id"].startswith("page/")],
+            "recent_pages": recent, "private_pages": private_items,
             "favorite_pages": [], "user": user,
             "workspace_key": ws_key}
 
@@ -455,9 +467,18 @@ async def create_page(request: Request, title: str = Query(default="New page"),
     user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
     ws_key = project if project else (user.get("login", "Bruno") if user else "Bruno")
     with get_conn() as conn:
+        # Compute next sort_order for this parent
+        next_order = 0
+        parent_val = parent_id if parent_id > 0 else None
+        row = conn.execute(
+            "SELECT COALESCE(MAX(sort_order), -1) + 1 FROM pages WHERE workspace=? AND parent_id IS ?",
+            (ws_key, parent_val),
+        ).fetchone()
+        if row:
+            next_order = row[0]
         cur = conn.execute(
-            "INSERT INTO pages (workspace, title, parent_section, parent_id) VALUES (?,?,?,?)",
-            (ws_key, title, section, parent_id if parent_id > 0 else None),
+            "INSERT INTO pages (workspace, title, parent_section, parent_id, sort_order) VALUES (?,?,?,?,?)",
+            (ws_key, title, section, parent_val, next_order),
         )
         conn.commit()
         page_id = cur.lastrowid
@@ -487,6 +508,45 @@ async def update_page(page_id: int, title: str = Query(default=""),
     return {"status": "ok"}
 
 
+@router.put("/api/pages/{page_id}/move")
+async def move_page(request: Request, page_id: int,
+                     new_parent_id: int = Query(default=0),
+                     new_order: int = Query(default=0)):
+    """Move/reorder a page in the tree (drag & drop).
+    new_parent_id=0 means move to root level.
+    new_order=0 means append to end (or set explicit position)."""
+    with get_conn() as conn:
+        # Verify page exists
+        row = conn.execute("SELECT id, workspace FROM pages WHERE id=?", (page_id,)).fetchone()
+        if not row:
+            raise HTTPException(404, "Page not found")
+        # Update parent (None for root level)
+        conn.execute(
+            "UPDATE pages SET parent_id=?, updated_at=CURRENT_TIMESTAMP WHERE id=?",
+            (new_parent_id if new_parent_id > 0 else None, page_id),
+        )
+        # Update sort order
+        conn.execute(
+            "UPDATE pages SET sort_order=?, updated_at=CURRENT_TIMESTAMP WHERE id=?",
+            (new_order, page_id),
+        )
+        # Re-index siblings to ensure no gaps
+        siblings = conn.execute(
+            "SELECT id, sort_order FROM pages WHERE workspace=? AND parent_id IS ? AND id != ? ORDER BY sort_order ASC",
+            (row["workspace"], new_parent_id if new_parent_id > 0 else None, page_id),
+        ).fetchall()
+        # Recompute sort_order for all siblings after the insertion point
+        insert_point = new_order
+        reorder = []
+        for sib in siblings:
+            if sib["sort_order"] >= insert_point:
+                reorder.append(sib["id"])
+        for i, sid in enumerate(sorted(reorder, key=lambda x: next(s["sort_order"] for s in siblings if s["id"] == x))):
+            conn.execute("UPDATE pages SET sort_order=? WHERE id=?", (insert_point + i + 1, sid))
+        conn.commit()
+    return {"status": "ok", "id": page_id, "parent_id": new_parent_id, "order": new_order}
+
+
 @router.get("/pages/{page_id}", response_class=HTMLResponse)
 async def view_page(request: Request, page_id: int):
     """Render a page as HTML."""

app/routers/dashboard.py

@@ -29,6 +29,9 @@ def _sidebar_data(request: Request, repos: list[dict]) -> dict:
             "url": f"/board/{full_name}",
             "active": False,
             "indent": 0,
+            "depth": 0,
+            "has_children": False,
+            "children": [],
         })
 
     return {