UI styling improvements: dashboard headers and navigation

- Restore blue PageHeader on Dashboard (/app-components)
- Update homepage (/) with subtle header design without blue bar
- Add uniform PageHeader styling to application edit page
- Fix Rapporten link on homepage to point to /reports overview
- Improve header descriptions spacing for better readability

backend/src/services/database/normalized-schema-init.ts

@@ -0,0 +1,43 @@
+/**
+ * Database Schema Initialization
+ * 
+ * Ensures normalized EAV schema is initialized before services use it.
+ */
+
+import { getDatabaseAdapter } from './singleton.js';
+import { NORMALIZED_SCHEMA_POSTGRES, NORMALIZED_SCHEMA_SQLITE } from './normalized-schema.js';
+import { logger } from '../logger.js';
+
+let initialized = false;
+let initializationPromise: Promise<void> | null = null;
+
+/**
+ * Ensure database schema is initialized
+ */
+export async function ensureSchemaInitialized(): Promise<void> {
+  if (initialized) return;
+  if (initializationPromise) {
+    await initializationPromise;
+    return;
+  }
+
+  initializationPromise = (async () => {
+    try {
+      // Use shared database adapter singleton
+      const db = getDatabaseAdapter();
+      const isPostgres = db.isPostgres === true;
+
+      // Execute schema
+      const schema = isPostgres ? NORMALIZED_SCHEMA_POSTGRES : NORMALIZED_SCHEMA_SQLITE;
+      await db.exec(schema);
+
+      logger.info(`Database schema initialized (${isPostgres ? 'PostgreSQL' : 'SQLite'})`);
+      initialized = true;
+    } catch (error) {
+      logger.error('Failed to initialize database schema', error);
+      throw error;
+    }
+  })();
+
+  await initializationPromise;
+}