feat(hub): built-in PBank 题库 capability + role tools (v0.0.42)

Register pbank as an ADR-0027 external capability with org-scoped
username/password envelopes, readiness via /login, and in-process
cph_hub MCP tools (search/get/get_many) that materialize sources under
the run workspace. Extend the capability secret payload for docmind vs
pbank kinds, admin capabilities UI, role tool umbrella `pbank`, and the
pbank-problem-report skill. Credentials never reach the Agent process.

hub/admin-web/src/lib/constants.ts

@@ -18,6 +18,8 @@ export const TOOL_OPTIONS: ToolOption[] = [
 	{ id: 'feishu_read_context', label: '读飞书上下文', group: '飞书' },
 	{ id: 'feishu_download_resource', label: '下载飞书资源', group: '飞书' },
 	{ id: 'request_approval', label: '请求审批', group: '飞书' },
+	{ id: 'convert_pdf_to_md', label: 'PDF→Markdown', group: '能力' },
+	{ id: 'pbank', label: '题库 (PBank)', group: '能力' },
 ];
 
 /** 组织成员角色（接口枚举保持英文，界面用 orgRoleLabel） */