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/components/note-editor/note-editor-toolbar.tsx

@@ -330,7 +330,7 @@ export function NoteEditorToolbar({ mode, onClose, onToggleAttachments, attachme
           duration: 6000,
         })
       } else {
-        toast.error(data.error || t('general.error'))
+        toast.error(data.errorKey ? t(data.errorKey) : (data.error || t('general.error')))
       }
     } catch {
       toast.error(t('general.error'))
@@ -408,7 +408,7 @@ export function NoteEditorToolbar({ mode, onClose, onToggleAttachments, attachme
         })
       } else {
         toast.dismiss(toastId)
-        toast.error(data.error || t('general.error'))
+        toast.error(data.errorKey ? t(data.errorKey) : (data.error || t('general.error')))
       }
     } catch {
       toast.dismiss(toastId)
@@ -437,7 +437,7 @@ export function NoteEditorToolbar({ mode, onClose, onToggleAttachments, attachme
         setPublishOpen(false)
       } else {
         const data = await res.json().catch(() => ({}))
-        toast.error(data.error || t('general.error'))
+        toast.error(data.errorKey ? t(data.errorKey) : (data.error || t('general.error')))
       }
     } catch {
       toast.error(t('general.error'))