Add configurable news research backfill and coverage reporting

Allow selecting a historical start time and checking unfinished news before enabling analysis. Report enrolled work outside the selected range and use the active server boundary while retaining paused drafts. Cover date validation, queue carryover, task completion and cross-tab responses.

web/src/common/apis/news-research/index.ts

@@ -3,7 +3,8 @@ import { request } from "@/http/axios"
 
 export const getSettingsApi = () => request<Research.Settings>({ url: "/risk/settings", method: "get" })
 export const saveSettingsApi = (data: Research.Config) => request<null>({ url: "/risk/settings", method: "put", data })
-export const enableApi = () => request<null>({ url: "/risk/enable", method: "post" })
+export const enableApi = (start_at: string) => request<Research.Coverage>({ url: "/risk/enable", method: "post", data: { start_at } })
+export const getCoverageApi = (start_at: string) => request<Research.Coverage>({ url: "/risk/coverage", method: "get", params: { start_at } })
 export const pauseApi = () => request<null>({ url: "/risk/pause", method: "post" })
 export const createSkillsApi = () => request<{ index: number, research: number }>({ url: "/risk/skill-templates", method: "post" })
 export const listEventsApi = (q: string, page: number) => request<{ items: Research.Event[], total: number }>({ url: "/risk/events", method: "get", params: { q, page } })