feat: align PostHog API host with airi.build

apps/server/docs/ai-context/metrics-ownership.md

@@ -179,7 +179,7 @@ posthog.capture('pricing_page_viewed', { plan_period, source })
 import posthog from 'posthog-js/dist/module.full.no-external.js'
 
 posthog.init(import.meta.env.VITE_POSTHOG_KEY, {
-  api_host: 'https://us.i.posthog.com',
+  api_host: 'https://t.airi.build',
   autocapture: false, // 桌面应用没有传统 URL 路由，手动控制
 })
 ```

apps/server/src/libs/env.ts

@@ -181,7 +181,7 @@ const EnvSchema = object({
   // the box. Set to an empty string to disable; Postgres `product_events`
   // stays the source of truth either way.
   POSTHOG_PROJECT_KEY: optional(string(), 'phc_pzjziJjrVZpa9SqnQqq0QEKvkmuCPH7GDTA6TbRTEf9'), // cspell:disable-line
-  POSTHOG_API_HOST: optional(string(), 'https://us.i.posthog.com'),
+  POSTHOG_API_HOST: optional(string(), 'https://t.airi.build'),
 
   // OpenTelemetry
   OTEL_SERVICE_NAMESPACE: optional(string(), 'airi'),

posthog.config.ts

@@ -20,7 +20,7 @@ export const POSTHOG_PROJECT_KEY
     ?? 'phc_pzjziJjrVZpa9SqnQqq0QEKvkmuCPH7GDTA6TbRTEf9' // cspell:disable-line
 
 export const DEFAULT_POSTHOG_CONFIG = {
-  api_host: 'https://us.i.posthog.com',
+  api_host: 'https://t.airi.build',
   person_profiles: 'identified_only', // or 'always' to create profiles for anonymous users as well
   // Without this, posthog-js only fires `$pageview` on the initial page load.
   // Every AIRI surface is an SPA (vue-router / VitePress client routing), so