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>

frontend/composables/useAppVersion.ts

@@ -0,0 +1,17 @@
+export function useAppVersion() {
+    const api = useApi()
+    const version = useState<string | null>('app-version', () => null)
+
+    async function load(): Promise<string | null> {
+        if (version.value) {
+            return version.value
+        }
+        const response = await api.get<{ version: string }>('version', {}, {
+            toast: false
+        })
+        version.value = response.version
+        return version.value
+    }
+
+    return { version, load }
+}