initial: split from gov-agreg — vreau.digital standalone platform

Moved from gov-agreg/src/pages/achizitii/* to root (drop prefix).
- 22 pages migrated, 127 files total
- All internal links: /achizitii/X → /X (176 occurrences fixed)
- AchizitiiLayout subnav rewritten: /X paths, top-right link to vreaudigital.ro hub
- BaseLayout new (vreau.digital branding, OG tags, site URL)
- astro.config.mjs: site https://vreau.digital, server output (was static)
- docker-compose: port 5096 (vreaudigital is 5095), container vreau-digital
- deploy.sh: paths /opt/vreau-digital, log /var/log/vreau-digital-deploy.log

Backend shared with gov-agreg:
- PostgreSQL satra (same schemas: seap, firms, anaf, anre, ...)
- Photon, Martin tiles
- Infisical /vreaudigital path (DATABASE_URL etc. shared)

build: PASS (npx astro check 0 errors, npm run build 5s vite + 10s server)

nginx.conf

@@ -0,0 +1,26 @@
+server {
+    listen 80;
+    server_name _;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # Gzip
+    gzip on;
+    gzip_types text/plain text/css application/json application/javascript text/xml application/xml text/javascript image/svg+xml;
+    gzip_min_length 256;
+
+    # Cache static assets
+    location /_astro/ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+    }
+
+    # SPA fallback
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    # Security headers (Traefik adds more, these are nginx-level)
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header X-Frame-Options "SAMEORIGIN" always;
+}