feat : init Central project — Symfony 8 + Nuxt 4 + Docker starter

Same architecture as Lesstime: API Platform 4, JWT auth, @malio/layer-ui,
PostgreSQL 16, Docker Compose (ports 8083/3003/5436), dark mode theme.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

config/packages/api_platform.yaml

@@ -0,0 +1,12 @@
+api_platform:
+    title: Central API
+    version: 1.0.0
+    formats:
+        jsonld: ['application/ld+json']
+        json: ['application/json']
+    patch_formats:
+        json: ['application/merge-patch+json']
+    defaults:
+        stateless: true
+        cache_headers:
+            vary: ['Content-Type', 'Authorization', 'Origin']