[robinv8]

Summary

When auto-install validation fails, the environment variable reference does not identify which settings are required or what values they accept. This update documents the required settings, their validation limits, and the connection variables for each database. It also adds a complete SQLite command that initializes a fresh data directory.

Validation

• Ran the exact SQLite example with an Answer binary built from apache/answer dev at 0584ca0. Confirmed the generated configuration, initialized SQLite database, admin account, and saved site settings.
• Ran the Docusaurus production build for English and Simplified Chinese with Node 20 and pnpm 9.

Fixes #359.