docs: update second interim delivery status

[alekskjo]

Summary

• document the verified second interim delivery flow from the published React client through GraphQL to PostgreSQL
• add the published Project 2 URL and public GraphQL path
• replace stale statements about mock data and a planned backend service
• record the verified persistent API and Apache proxy status

Verification

• Prettier check passes for all changed Markdown files
• git diff --check passes
• published frontend loads 51 venues, opens venue details and still works after a full reload
• public GraphQL endpoint reports health: ok, databaseStatus: connected and 51 venues

[erikbsa]

Clear and concise summary. Good change by having one language as the standard. Approved.