fix(settings): remove the duplicated section heading on 11 tabs

A generic shell heading stacked on top of each tab component's own internal
heading. The report named five tabs "at least"; auditing all 28 found 11:
downloads, sso, apiTokens, webhooks, businessProfile, crm, accounting,
whatsapp, slideshow, moderation, styling. On the first eight the two headings
resolve to the identical string -- sso and businessProfile literally render
the same key twice. The other three were near-identical stacked titles
("Moderation"/"Word Filters", "Custom CSS"/"Custom CSS Templates",
"CRM behaviour"/"CRM settings").

Clean, and left alone: general, events, categories, thumbnails, security, seo,
imageSecurity, status, analytics (its first heading is a genuine sub-section),
plus the eight already in TABS_WITH_OWN_HEADER.

Removed the component side and kept the shell heading: the shell heading is
the consistent one (icon + label + divider on ~20 tabs) and always matches the
nav item the admin clicked, and none of these components are mounted outside
SettingsPage, so nothing loses a title. Subtitles and intro copy preserved
throughout; orphaned icon imports removed.

The guard test was checked against the pre-fix blobs and does fail on them.

Refs testplan REPORT.md, "duplicate H2 section heading" warning.

frontend/src/features/settings/tabs/AccountingTab.tsx

@@ -95,10 +95,12 @@ export const AccountingTab: React.FC = () => {
 
   return (
     <div className="space-y-6">
-      <div>
-        <h2 className="text-xl font-bold text-neutral-900 dark:text-neutral-100">{t('settings.accounting.title', 'Accounting')}</h2>
-        <p className="text-neutral-600 dark:text-neutral-400 mt-1">{t('settings.accounting.subtitle', 'Default rates for internal expenses and the proof requirement.')}</p>
-      </div>
+      {/* No tab title here — the Settings shell renders the section
+          heading (icon + label + divider) for every tab that isn't in
+          SettingsPage's TABS_WITH_OWN_HEADER, and it reads from the same
+          `settings.accounting.title` key, so repeating it stacked two
+          identical H2s on top of each other (QA warning). */}
+      <p className="text-neutral-600 dark:text-neutral-400">{t('settings.accounting.subtitle', 'Default rates for internal expenses and the proof requirement.')}</p>
 
       <Card><CardContent className="p-5 space-y-4">
         <div>

frontend/src/features/settings/tabs/ApiTokensTab.tsx

@@ -2,7 +2,7 @@ import React, { useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { toast } from 'react-toastify';
-import { KeyRound, Trash2, Copy, AlertTriangle } from 'lucide-react';
+import { Trash2, Copy, AlertTriangle } from 'lucide-react';
 import { Button, Card, Input, Loading } from '../../../components/common';
 import { api } from '../../../config/api';
 import { useLocalizedDate } from '../../../hooks/useLocalizedDate';
@@ -83,10 +83,10 @@ export const ApiTokensTab: React.FC = () => {
   return (
     <div className="space-y-6">
       <Card padding="md">
-        <h2 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100 mb-2 flex items-center gap-2">
-          <KeyRound className="w-5 h-5" />
-          {t('settings.apiTokens.title', 'API Tokens')}
-        </h2>
+        {/* No tab title here — the Settings shell renders the section
+            heading (icon + label + divider) for every tab that isn't in
+            SettingsPage's TABS_WITH_OWN_HEADER, and repeating it stacked
+            two identical H2s on top of each other (QA warning). */}
         <p className="text-sm text-neutral-600 dark:text-neutral-400 mb-4">
           {t('settings.apiTokens.subtitle', 'Long-lived bearer tokens for the public /api/v1 surface — n8n integrations, custom apps, scripts. Tokens act as the admin user that minted them, intersected with the chosen scopes.')}
         </p>

frontend/src/features/settings/tabs/DownloadsTab.tsx

@@ -1,5 +1,5 @@
 import React, { useEffect, useState } from 'react';
-import { Save, Download, Plus, Trash2 } from 'lucide-react';
+import { Save, Plus, Trash2 } from 'lucide-react';
 import { useTranslation } from 'react-i18next';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { toast } from 'react-toastify';
@@ -107,12 +107,10 @@ export const DownloadsTab: React.FC = () => {
   return (
     <div className="space-y-6">
       <Card>
-        <div className="flex items-center gap-2 mb-1">
-          <Download className="w-5 h-5 text-neutral-500" />
-          <h2 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100">
-            {t('settings.downloads.title', 'Download resolutions')}
-          </h2>
-        </div>
+        {/* No tab title here — the Settings shell renders the section
+            heading (icon + label + divider) for every tab that isn't in
+            SettingsPage's TABS_WITH_OWN_HEADER, and repeating it stacked
+            two identical H2s on top of each other (QA warning). */}
         <p className="text-sm text-neutral-600 dark:text-neutral-400 mb-5">
           {t('settings.downloads.intro',
             'The standard size is what every gallery hands out by default. Individual galleries can override this.')}

frontend/src/features/settings/tabs/SsoTab.tsx

@@ -2,7 +2,7 @@ import React, { useState } from 'react';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { useTranslation } from 'react-i18next';
 import { toast } from 'react-toastify';
-import { Save, KeyRound, PlugZap, Copy, Check, UserCog, ShieldAlert, Plus, Trash2 } from 'lucide-react';
+import { Save, PlugZap, Copy, Check, UserCog, ShieldAlert, Plus, Trash2 } from 'lucide-react';
 import type { AxiosError } from 'axios';
 
 import { Button, Card, Input, Loading } from '../../../components/common';
@@ -127,12 +127,11 @@ export const SsoTab: React.FC = () => {
     <div className="space-y-6">
       <Card>
         <div className="p-6 space-y-4">
-          <div className="flex items-center gap-2">
-            <KeyRound className="w-5 h-5 text-neutral-500" />
-            <h2 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100">
-              {t('settings.sso.title', 'Single Sign-On (OIDC)')}
-            </h2>
-          </div>
+          {/* No tab title here — the Settings shell renders the section
+              heading (icon + label + divider) for every tab that isn't in
+              SettingsPage's TABS_WITH_OWN_HEADER, and it reads from the
+              same `settings.sso.title` key, so repeating it stacked two
+              identical H2s on top of each other (QA warning). */}
           <p className="text-sm text-neutral-600 dark:text-neutral-400">
             {t('settings.sso.intro', 'Let admins sign in through your identity provider (Keycloak, Authentik, Pocket ID, or any OIDC-compliant IdP). Local email/password login stays available as a fallback.')}
           </p>

frontend/src/features/settings/tabs/WebhooksTab.tsx

@@ -3,7 +3,7 @@ import { useTranslation } from 'react-i18next';
 import { Link } from 'react-router-dom';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { toast } from 'react-toastify';
-import { Webhook as WebhookIcon, Trash2, Copy, AlertTriangle, Activity, CheckCircle2, XCircle } from 'lucide-react';
+import { Trash2, Copy, AlertTriangle, Activity, CheckCircle2, XCircle } from 'lucide-react';
 import { Button, Card, Input, Loading } from '../../../components/common';
 import { api } from '../../../config/api';
 import { useLocalizedDate } from '../../../hooks/useLocalizedDate';
@@ -124,10 +124,10 @@ export const WebhooksTab: React.FC = () => {
   return (
     <div className="space-y-6">
       <Card padding="md">
-        <h2 className="text-lg font-semibold text-neutral-900 dark:text-neutral-100 mb-2 flex items-center gap-2">
-          <WebhookIcon className="w-5 h-5" />
-          {t('settings.webhooks.title', 'Webhooks')}
-        </h2>
+        {/* No tab title here — the Settings shell renders the section
+            heading (icon + label + divider) for every tab that isn't in
+            SettingsPage's TABS_WITH_OWN_HEADER, and repeating it stacked
+            two identical H2s on top of each other (QA warning). */}
         <p className="text-sm text-neutral-600 dark:text-neutral-400 mb-4">
           {t('settings.webhooks.subtitle', 'POST event notifications to your URL the moment something happens — gallery published, photo uploaded, event archived, etc. Signed with HMAC-SHA256 in the X-PicPeak-Signature header.')}
         </p>

frontend/src/features/settings/tabs/WhatsAppTab.tsx

@@ -119,17 +119,17 @@ export const WhatsAppTab: React.FC = () => {
 
   return (
     <div className="space-y-6">
-      <div>
-        <h2 className="text-xl font-bold text-neutral-900 dark:text-neutral-100">
-          {t('settings.whatsapp.title', 'WhatsApp')}
-        </h2>
-        <p className="text-neutral-600 dark:text-neutral-400 mt-1">
-          {t(
-            'settings.whatsapp.subtitle',
-            'Configure Meta Business credentials to deliver the gallery-ready notification via WhatsApp alongside email.',
-          )}
-        </p>
-      </div>
+      {/* No tab title here — the Settings shell renders the section
+          heading (icon + label + divider) for every tab that isn't in
+          SettingsPage's TABS_WITH_OWN_HEADER, and it reads from the same
+          `settings.whatsapp.title` key, so repeating it stacked two
+          identical H2s on top of each other (QA warning). */}
+      <p className="text-neutral-600 dark:text-neutral-400">
+        {t(
+          'settings.whatsapp.subtitle',
+          'Configure Meta Business credentials to deliver the gallery-ready notification via WhatsApp alongside email.',
+        )}
+      </p>
 
       <Card>
         <CardContent className="p-5 space-y-4">