feat(FN-3786): add reports dashboard view and comparison tooling

Adds a Reports dashboard view (`ReportsView`) to the reports plugin with a full supporting stack of components (`ReportComparisonDrawer`, `ReportDetailPanel`, `ReportFiltersBar`, `ReportListItem`, `ReportEmptyState`), hooks (`useReports`, `useReportPreview`, `useReportSectionDiff`, `useViewportMode`

Fusion-Task-Id: FN-3786

plugins/fusion-plugin-reports/src/dashboard/api.ts

@@ -0,0 +1,53 @@
+import type { ReportRecord } from "./types.js";
+
+const BASE = "/api/plugins/reports";
+
+interface ListReportsParams {
+  cadence?: string;
+  status?: string;
+  from?: string;
+  to?: string;
+  q?: string;
+  agentId?: string;
+  projectId?: string;
+}
+
+function qp(params: Record<string, string | undefined>): string {
+  const entries = Object.entries(params).filter(([, value]) => typeof value === "string" && value.length > 0) as Array<[string, string]>;
+  if (entries.length === 0) return "";
+  return `?${entries.map(([k, v]) => `${encodeURIComponent(k)}=${encodeURIComponent(v)}`).join("&")}`;
+}
+
+async function request<T>(path: string, init?: RequestInit, responseType: "json" | "text" = "json"): Promise<T> {
+  const response = await fetch(`${BASE}${path}`, init);
+  if (!response.ok) {
+    let message = `${response.status} ${response.statusText}`;
+    try {
+      const data = (await response.json()) as { error?: string };
+      if (data.error) message = data.error;
+    } catch {
+      // ignore
+    }
+    throw new Error(message);
+  }
+  if (responseType === "text") return (await response.text()) as T;
+  return (await response.json()) as T;
+}
+
+export async function listReports(params: ListReportsParams = {}): Promise<ReportRecord[]> {
+  const data = await request<{ reports: ReportRecord[] }>(`/reports${qp({ ...params })}`);
+  return data.reports;
+}
+
+export async function getReport(id: string, projectId?: string): Promise<ReportRecord> {
+  const data = await request<{ report: ReportRecord }>(`/reports/${encodeURIComponent(id)}${qp({ projectId })}`);
+  return data.report;
+}
+
+export function getReportPreviewHtml(id: string, projectId?: string): Promise<string> {
+  return request<string>(`/reports/${encodeURIComponent(id)}/preview.html${qp({ projectId })}`, undefined, "text");
+}
+
+export function getReportExportUrl(id: string, projectId?: string): string {
+  return `${BASE}/reports/${encodeURIComponent(id)}/export.html${qp({ projectId })}`;
+}