[codex] Add first-use measurement

[iteration-machine-dev]

What changed

• Added explicit first-use analytics events for share creation, edit-link opens, saves, GitHub connection, repo sync, and push-back.
• Tagged events with flow: anonymous_share or flow: github_workspace so the two first-use paths can be separated in analytics.
• Added shared payload sanitization so document content, markdown, source text, secrets, tokens, and request bodies are not sent with first-use events.

Impact

This makes the real first-use win measurable instead of relying only on generic product event volume. Analytics can now answer whether someone created a share, opened an edit link, saved, connected GitHub, synced a repo, and pushed changes back.

Validation

• npm --workspace web run test
• npx tsc --noEmit -p hocuspocus-server/tsconfig.json
• npm --workspace web run build
• git diff --check

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
with-md-web	Ready	Preview, Comment	Jun 7, 2026 2:18pm