fix(ci): resolve langbot-plugin from PyPI and clear lint failures

CI on feat/sandbox failed across Unit Tests, Lint and Build Dev Image.
Root causes and fixes:

- pyproject.toml had a [tool.uv.sources] editable override pinning
  langbot-plugin to ../langbot-plugin-sdk. That path only exists in a
  paired local checkout, so `uv sync` failed on every CI runner
  ("Distribution not found"). Remove the override and regenerate uv.lock
  so langbot-plugin==0.4.0b1 resolves from PyPI, matching master.

- tests/integration/api/test_pipelines.py: the pipeline extensions
  endpoint now calls ap.skill_service.list_skills(); add the missing
  skill_service mock to the fake_pipeline_app fixture (the test came
  from master, the endpoint change from feat/sandbox).

- Apply ruff format to three src files and prettier to three web files
  that had committed formatting drift, failing `ruff format --check`
  and `pnpm lint`.

src/langbot/pkg/api/http/controller/groups/resources/mcp.py

@@ -32,6 +32,7 @@ class MCPRouterGroup(group.RouterGroup):
         async def _(server_name: str) -> str:
             """获取、更新或删除MCP服务器配置"""
             from urllib.parse import unquote
+
             server_name = unquote(server_name)
 
             server_data = await self.ap.mcp_service.get_mcp_server_by_name(server_name)
@@ -60,6 +61,7 @@ class MCPRouterGroup(group.RouterGroup):
         async def _(server_name: str) -> str:
             """测试MCP服务器连接"""
             from urllib.parse import unquote
+
             server_name = unquote(server_name)
             server_data = await quart.request.json
             task_id = await self.ap.mcp_service.test_mcp_server(server_name=server_name, server_data=server_data)