feat(sprint-5.5): add NestJS API, BlockMetaBar, block components + fix Vercel build

- Add vercel.json to build only apps/web (fix Vercel build failure)
- NestJS API: BlocksModule, BlocksController, BlocksService with Prisma 7
- PostgreSQL migration: Block model (path, version, isInPreview)
- BlockMetaBar component: inline version edit, API fetch with offline fallback
- New block components: CeoBlock, ContactFormsBlock, FooterBlock, NewsBlock, ReviewsBlock
- PreviewClient: fetch isInPreview from API, block visibility toggle
- Pages updated: hero, doctors, ceo, contact-forms, contact, news, reviews
- docker-compose: PostgreSQL on port 5434

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/app/components/buttons/page.tsx

@@ -2,6 +2,7 @@ import type { Metadata } from "next";
 import { Button } from "@/components/ui/Button";
 import { CodeCopy } from "@/components/ui/CodeCopy";
 import { LlmBlock, LlmSection, LlmTable, LlmRules } from "@/components/llm/LlmBlock";
+import { BlockMetaBar } from "@/components/ui/BlockMetaBar";
 
 export const metadata: Metadata = {
   title: "Кнопки. Цифровой брендбук Клиники ухо, горло, нос им. проф. Е.Н.Оленевой",
@@ -227,6 +228,7 @@ a.callback_url {
         <h1 className="text-3xl font-semibold mb-3" style={{ color: "var(--bb-text)" }}>
           Кнопки
         </h1>
+        <BlockMetaBar path="/components/buttons" defaultVersion="v2.0" defaultIsInPreview={false} />
         <p className="text-base max-w-2xl" style={{ color: "var(--bb-text-muted)" }}>
           Кнопки скопированы с реального сайта{" "}
           <span className="font-mono text-sm" style={{ color: "var(--bb-text)" }}>