feat(ui,api): wave 3 — editorial pricing, real cancel, server history, DeepL purge

Pricing: full editorial redesign — serif card headers with accent pills
replace the colored font-black blocks, tone sweep across toggle/metrics/
features/CTAs, PLAN_COLORS removed; one design system app-wide.

Translate: decorative titles one step down (CTA hierarchy restored);
glossary and image-translation blocks hidden entirely for free users
(progressive disclosure — three controls for free).

Reviews: XLIFF hint line explains the exchange format; backend errors
routed through a friendly mapper (session/not-found/rate-limit/server).

Landing: fabricated hero UI cards (fake 'Context Engine' overlay)
removed — the photo no longer promises screens that don't exist.

Nav: single DashboardNavLinks component shared by sidebar and mobile
drawer (was duplicated markup).

API: GET /api/v1/translations (user job history, paginated; completed
jobs retained 24h) and POST /api/v1/translations/{id}/cancel —
cooperative cancellation with worker checkpoints before dispatch and
before finalisation, reserved quota released immediately. Translate
monitor now offers a real 'Cancel translation' next to 'Back to start';
recent-jobs list reads server history first, localStorage fallback.

DeepL purge (backend): provider module, registry registration, config
attrs/defaults, dispatch branch, admin settings schema + test branch,
legacy availability block, validation rules, plan provider lists,
error-code mappings, MCP enums, translator prompt mention, related
tests updated/removed. Fallback resolver skips unknown providers, so
stale chains containing 'deepl' degrade gracefully.

Verified: backend 110 tests passed; frontend build exit 0, vitest 9/9,
0 missing i18n keys, eslint 63 errors (vs 64 at HEAD).

frontend/src/app/dashboard/translate/useTranslationSubmit.ts

@@ -22,6 +22,30 @@ interface StoredJob { jobId: string; fileName: string | null; savedAt: number }
 
 export interface RecentJob { jobId: string; fileName: string; completedAt: number }
 
+/** Server history (last jobs, newest first) — empty when offline/unauthenticated. */
+export async function fetchServerHistory(perPage = 6): Promise<RecentJob[]> {
+  if (typeof window === 'undefined') return [];
+  const token = localStorage.getItem('token');
+  if (!token) return [];
+  try {
+    const res = await fetch(`${API_BASE}/api/v1/translations?per_page=${perPage}`, {
+      headers: { Authorization: `Bearer ${token}` },
+    });
+    if (!res.ok) return [];
+    const json = await res.json();
+    return (json.data ?? []).map((j: {
+      id: string; file_name?: string | null;
+      completed_at?: string | null; created_at?: string | null;
+    }) => ({
+      jobId: j.id,
+      fileName: j.file_name ?? '',
+      completedAt: Date.parse(j.completed_at ?? j.created_at ?? '') || Date.now(),
+    }));
+  } catch {
+    return [];
+  }
+}
+
 export function getRecentJobs(): RecentJob[] {
   if (typeof window === 'undefined') return [];
   try {
@@ -235,6 +259,28 @@ export function useTranslationSubmit(): UseTranslationSubmitReturn {
     // NOTE: Don't set isSubmitting(false) here - let polling handle the transition
   }, [startPolling]);
 
+  /** Ask the backend to cancel the current job. Returns true on success. */
+  const cancelJob = useCallback(async (): Promise<boolean> => {
+    const id = jobId;
+    if (!id) return false;
+    try {
+      const token = localStorage.getItem('token');
+      const headers: Record<string, string> = {};
+      if (token) headers['Authorization'] = `Bearer ${token}`;
+      const res = await fetch(`${API_BASE}/api/v1/translations/${id}/cancel`, {
+        method: 'POST',
+        headers,
+      });
+      if (!res.ok) return false;
+      stopPolling();
+      persistActiveJob(null);
+      setIsSubmitting(false);
+      return true;
+    } catch {
+      return false;
+    }
+  }, [jobId, stopPolling]);
+
   const reset = useCallback(() => {
     stopPolling();
     persistActiveJob(null);
@@ -285,6 +331,7 @@ export function useTranslationSubmit(): UseTranslationSubmitReturn {
 
   return {
     submitTranslation,
+    cancelJob,
     jobId,
     status,
     progress,