feat(scheduler): per-job help tooltips, status legend, inline interval edit

Each job shows a tooltip (what it does + what happens if it stops), a status
dot legend + per-dot tooltips clarify the colours, and the interval is inline-
editable (pencil -> number -> save) wired to the new PATCH endpoint. HU/EN/DE.

frontend/src/lib/api.ts

@@ -434,6 +434,11 @@ export const api = {
   myUsage: (): Promise<MyUsage> => req("/api/quota/my-usage"),
   adminQuota: (days = 30): Promise<AdminQuota> => req(`/api/quota/admin?days=${days}`),
   schedulerStatus: (): Promise<SchedulerStatus> => req("/api/admin/scheduler"),
+  updateSchedulerJob: (jobId: string, intervalMinutes: number): Promise<{ id: string; interval_minutes: number }> =>
+    req(`/api/admin/scheduler/jobs/${jobId}`, {
+      method: "PATCH",
+      body: JSON.stringify({ interval_minutes: intervalMinutes }),
+    }),
 
   // --- onboarding / admin ---
   requestAccess: (email: string): Promise<{ status: string }> =>