fix(capital): auto-generate CPP doc preview on step entry, restore section header formatting

Preview for ГЕНЕРАТОР/БЛАГОРОСТ params no longer requires a manual button click on
first visit — onMounted now calls ensurePreview for the active wizard step. Also
fixes wizardStepOrder typing (was narrower than the runtime string values it holds).

Restores <h3> centered section-title markup in registry templates 994/995/996/998/999/1000
that was lost during the "parameterize CPP templates via private data" refactor, when
translations+context i18n structure was flattened into raw HTML.

components/desktop/extensions/capital/features/Onboarding/ui/CapitalOnboardingCard.vue

@@ -181,7 +181,7 @@ const wizardSteps = computed<StepperStep[]>(() => [
   })),
 ]);
 
-const wizardStepOrder = computed(() => [
+const wizardStepOrder = computed<string[]>(() => [
   ...DOC_WIZARD_STEP_ORDER,
   ...COUNCIL_STEP_GROUP_ORDER,
 ]);
@@ -439,6 +439,13 @@ onMounted(async () => {
   setWizardStepKey(normalizeWizardStepKey(activeWizardStep.value));
   syncWizardStepWithCouncilProgress();
 
+  if (isDocWizardStep(activeWizardStep.value)) {
+    const registryId = getRegistryIdForDocWizardStep(activeWizardStep.value);
+    if (registryId != null) {
+      void ensurePreview(registryId);
+    }
+  }
+
   if (shouldPollCouncilState.value) {
     startCouncilPoll();
   }