fix(knowledge): 分类侧栏按树的顺序排，已发布的知识也能直接改

两个都是"看着不对劲"的问题：

1. 侧栏把二级分类全堆在一级分类后面（按 depth 排序的副作用），
   「技术」和它的上级「我的备忘」隔着十几行，看着像一棵假树。
   后端改成按树的先序返回（父分类后紧跟它的子分类，兄弟仍按 sort_order、name），
   前端照 depth 缩进就是个真树；二级以下再加一个「·」标记，小屏也分得清。

2. 点开已发布的知识只有「归档」，没有改的入口——因为后端原来硬性拒绝
   修改已发布内容（7003）。但"发布"是给团队看的，写错了总要能改：
   现在已发布的可以直接 PATCH，改完立刻重建检索切片（chunk_count 当场更新），
   状态和版本号照常推进；归档的仍然要先「恢复成草稿」再改。

Web 与安卓同步：抽屉/详情里已发布也显示「编辑」，安卓分类标签区不再锁。

验证：pytest 95 passed（新增"分类按树返回"用例、发布后可改用例）、
ruff 全绿、tsc 0、vite build ✓；`knowledge-notebook.mjs` 17 项、
`knowledge.mjs` 9 项 e2e 全绿。安卓仍未编译（JDK 25 / Gradle 8.7 不兼容）。

backend/tests/test_knowledge.py

@@ -200,13 +200,18 @@ async def test_publish_requires_admin(client: AsyncClient) -> None:
     assert published["status"] == "published"
     assert published["knowledge"]["published_at"] is not None
 
-    # 已发布的内容不许直接改，先撤回
-    blocked = await client.patch(
-        f"{V1}/workspaces/{ws['id']}/knowledge/{doc['id']}",
-        json={"title": "值班手册 v2", "version": published["version"]},
-        headers=owner["headers"],
+    # 已发布的能直接改正文：改完后端自动重建切片，状态仍是已发布
+    edited = unwrap(
+        await client.patch(
+            f"{V1}/workspaces/{ws['id']}/knowledge/{doc['id']}",
+            json={"title": "值班手册 v2", "version": published["version"]},
+            headers=owner["headers"],
+        )
     )
-    assert blocked.json()["code"] == 7003
+    assert edited["title"] == "值班手册 v2"
+    assert edited["knowledge"]["status_hint"] == "published"
+    assert edited["version"] == published["version"] + 1
+    published = edited
 
     archived = unwrap(
         await client.post(
@@ -218,6 +223,14 @@ async def test_publish_requires_admin(client: AsyncClient) -> None:
     assert archived["status"] == "archived"
     assert archived["knowledge"]["archived_at"] is not None
 
+    # 归档是先收起来；要改先恢复成草稿，免得改完还挂着"现役"的样子
+    blocked = await client.patch(
+        f"{V1}/workspaces/{ws['id']}/knowledge/{doc['id']}",
+        json={"title": "值班手册 v3", "version": archived["version"]},
+        headers=owner["headers"],
+    )
+    assert blocked.json()["code"] == 7003
+
 
 @pytest.mark.asyncio
 async def test_illegal_action_reports_allowed(client: AsyncClient) -> None:

backend/tests/test_knowledge_categories.py

@@ -303,3 +303,29 @@ async def test_patch_knowledge_accepts_doc_type_and_bumps_version(client: AsyncC
     assert patched["body_md"] == "改过的正文"
     assert patched["version"] == doc["version"] + 1
     assert {t["name"] for t in patched["tags"]} == {"写法"}
+
+
+@pytest.mark.asyncio
+async def test_categories_come_back_as_a_tree(client: AsyncClient) -> None:
+    """列表按「父在前、子紧跟」排：前端照着 depth 缩进才像一棵树。
+
+    之前按 (depth, sort_order) 排，二级分类全堆在一级后面，
+    侧栏看着像"所有一级在一起、所有二级在一起"。
+    """
+    user, ws_id = await _ws(client)
+    tech = await _category(client, user, ws_id, "技术开发")
+    biz = await _category(client, user, ws_id, "餐饮业务")
+    child = await _category(client, user, ws_id, "技术", tech["id"])
+    await _category(client, user, ws_id, "部署", child["id"])
+    assert biz["depth"] == 1
+
+    items = unwrap(
+        await client.get(f"{V1}/workspaces/{ws_id}/knowledge/categories", headers=user["headers"])
+    )["items"]
+    assert [i["name"] for i in items] == ["技术开发", "技术", "部署", "餐饮业务"]
+    assert [i["full_path"] for i in items] == [
+        "技术开发",
+        "技术开发 / 技术",
+        "技术开发 / 技术 / 部署",
+        "餐饮业务",
+    ]