The backend still uses the existing JSON files as the primary store.

An optional SQLite addon can mirror workshop registrations and RSVPs in parallel, so it does not change the current API behavior.

Set these environment variables for the backend process:

• SQLITE_ENABLED=true
• SQLITE_DB_PATH=../db/workshops-addon.sqlite (optional override)

If SQLITE_ENABLED is not set, the addon is disabled by default.

• workshop_prompt_runs: canonical input_json and output_json matching Python input.json and output.json
• rsvps: mirrored from /api/workshops/:id/rsvp

workshop_prompt_runs also keeps helper columns (organization/contact/topic/title) for easier filtering, but the JSON documents remain the source of truth.

If SQLite write/mirror fails, requests still succeed using the JSON flow.