fix(ui): wave 2 from critique re-run — AA contrast, unified PageHeader, checkout confirm

Nav: teams/settings/services back out of the nav until product-ready (user
decision); teams page was already half-finished (UUID member display is a
backend limitation).

Payment: explicit confirmation dialog (plan, amount, billing period, Stripe
note) before any redirect; ?plan= URL now pre-opens the dialog instead of
triggering a silent checkout.

Contrast AA sweep (71 replacements): functional micro-labels raised to
>=60-65% opacity and >=10px across sidebar, header, pricing, landing;
decorative all-caps 'interface' label removed.

Design unification: new PageHeader component (accent pill + serif
base/accent title) applied to settings, services, reviews, teams; pricing
header returned to the editorial voice (serif + accent pill); dead
GlossaryCard deleted.

i18n residuals: suggestion chips, 'Standard' provider label, notification
close, model-combobox strings extracted (+broken bg-surface/border-border-
subtle tokens fixed); ~45 new keys EN+FR; 13 dead keys removed; zero
missing keys verified.

Reviews: icon-only row actions now carry visible text; 'Approve all' is
two-step armed-confirm.

Accelerators: Ctrl/Cmd+Enter submits; arrow-key navigation in the language
combobox; recent-jobs history cap 8->20 with per-job download; source=target
config rejected; empty 'Master Quality' badge removed.

Cookie consent: reopenable via footer link, emoji replaced with drawn icon.

Verified: build exit 0, vitest 9/9, eslint 64 errors = previous level,
0 missing i18n keys.

frontend/src/components/layout/page-header.tsx

@@ -0,0 +1,40 @@
+'use client';
+
+import type { ReactNode } from 'react';
+
+/**
+ * Single editorial page header: accent pill + serif title (base + italic accent)
+ * + subtitle. Every dashboard surface uses this so the product speaks one voice.
+ */
+export function PageHeader({
+  pill,
+  titleBase,
+  titleAccent,
+  subtitle,
+  action,
+  className = '',
+}: {
+  pill: string;
+  titleBase: string;
+  titleAccent: string;
+  subtitle?: string;
+  action?: ReactNode;
+  className?: string;
+}) {
+  return (
+    <div className={`mb-10 flex flex-col gap-6 sm:flex-row sm:items-end sm:justify-between ${className}`}>
+      <div>
+        <span className="accent-pill mb-4 block w-fit">{pill}</span>
+        <h1 className="mb-3 text-4xl font-serif font-medium leading-tight tracking-tight text-brand-dark dark:text-white md:text-5xl">
+          {titleBase} <span className="italic">{titleAccent}</span>
+        </h1>
+        {subtitle && (
+          <p className="max-w-xl text-sm font-light leading-relaxed text-brand-dark/60 dark:text-white/60">
+            {subtitle}
+          </p>
+        )}
+      </div>
+      {action && <div className="shrink-0">{action}</div>}
+    </div>
+  );
+}