fix: replace raw ai_consent_required code with translatable message and consent prompt

- Centralize AI consent 403 responses in server-consent helpers
- Return human-readable message + code + i18n errorKey from all AI APIs
- Update dashboard and AI clients to detect code/errorKey and translate
- Add consent.ai.requiredToast i18n keys (fr/en)

memento-note/app/api/notes/publish/route.ts

@@ -4,7 +4,7 @@ import prisma from '@/lib/prisma'
 import { contentModerationService, type ModerationResult } from '@/lib/ai/services/content-moderation.service'
 import { publishEnhanceService } from '@/lib/ai/services/publish-enhance.service'
 import { reserveUsageOrThrow, QuotaExceededError } from '@/lib/entitlements'
-import { hasUserAiConsent } from '@/lib/consent/server-consent'
+import { hasUserAiConsent, aiConsentForbiddenResponse } from '@/lib/consent/server-consent'
 import { isPublishTemplateId } from '@/lib/publish/types'
 import { computePublishedSourceHash, renderPublishedTemplate, renderRewrittenTemplate } from '@/lib/publish/template-render'
 
@@ -115,7 +115,7 @@ export async function POST(request: NextRequest) {
 
     if (publishMode === 'ai') {
       if (!(await hasUserAiConsent())) {
-        return NextResponse.json({ error: 'ai_consent_required' }, { status: 403 })
+        return aiConsentForbiddenResponse()
       }
       if (!template || !isPublishTemplateId(template)) {
         return NextResponse.json({ error: 'Invalid template' }, { status: 400 })