DBP-84: 導入 PostHog 進行網站統計

[pan93412]

• feat: add PostHog client
• feat: add PostHog analyze
• feat(chat): instrument LLM usage
• feat(chat): make system prompt cachable

[linear]

DBP-84 導入 PostHog 進行網站統計

[vercel]

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Project	Deployment	Preview	Comments	Updated (UTC)
dbplay-app	Ready	Preview	Comment	Oct 6, 2025 1:14pm

[Copilot]

Pull Request Overview

Integrates PostHog analytics platform for website statistics and user behavior tracking, including instrumentation of LLM chat usage and implementation of prompt caching optimization.

• Added PostHog client configuration for both browser and server environments
• Implemented user identification and session management for analytics tracking
• Instrumented chat API to track LLM usage with user attribution and introduced prompt caching

Reviewed Changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
package.json	Added PostHog dependencies (@posthog/ai, posthog-js, posthog-node)
next.config.ts	Configured PostHog proxy rewrites and trailing slash handling
instrumentation-client.ts	Initialized PostHog client with API configuration
lib/posthog.rsc.ts	Created server-side PostHog client factory
providers/posthog-identifier.tsx	Component for user identification in PostHog
app/login/_components/posthog-resetter.tsx	Component to reset PostHog session on login page
app/login/page.tsx	Integrated PostHog session reset
app/(app)/layout.tsx	Added PostHog identifier to authenticated app layout
lib/auth.rsc.ts	Refactored auth function to return user info instead of boolean
app/api/chat/route.ts	Added LLM usage tracking and prompt caching with GraphQL fragment refactoring
gql/ files	Auto-generated GraphQL code updates from fragment changes

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

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[Copilot]

Pull Request Overview

Copilot reviewed 12 out of 13 changed files in this pull request and generated 1 comment.

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}