chore(core): Switch PostHog environment variables to EU region

packages/@n8n/config/src/configs/diagnostics.config.ts

@@ -2,13 +2,12 @@ import { Config, Env, Nested } from '../decorators';
 
 @Config
 class PostHogConfig {
-	/** PostHog project API key for product analytics. */
+	// Note : On cloud staging, the staging PostHog key is injected via the environment variable through middleware.
 	@Env('N8N_DIAGNOSTICS_POSTHOG_API_KEY')
-	apiKey: string = 'phc_4URIAm1uYfJO7j8kWSe0J8lc8IqnstRLS7Jx8NcakHo';
+	apiKey: string = 'phc_kMstNfAgBcBkWSh6KdsgN09heqqNe5VNmalHP1Ni9Q4';
 
-	/** PostHog API host URL. */
 	@Env('N8N_DIAGNOSTICS_POSTHOG_API_HOST')
-	apiHost: string = 'https://us.i.posthog.com';
+	apiHost: string = 'https://ph.n8n.io';
 }
 
 @Config

packages/@n8n/config/test/config.test.ts

@@ -390,8 +390,8 @@ describe('GlobalConfig', () => {
 			frontendConfig: '1zPn9bgWPzlQc0p8Gj1uiK6DOTn;https://telemetry.n8n.io',
 			backendConfig: '1zPn7YoGC3ZXE9zLeTKLuQCB4F6;https://telemetry.n8n.io',
 			posthogConfig: {
-				apiKey: 'phc_4URIAm1uYfJO7j8kWSe0J8lc8IqnstRLS7Jx8NcakHo',
-				apiHost: 'https://us.i.posthog.com',
+				apiKey: 'phc_A1F0pkCo7km1rPwWPNyEW4MfRMDe2XijLYR50fs9DZm', // Staging key
+				apiHost: 'https://ph.n8n.io',
 			},
 		},
 		aiAssistant: {