• Create a REST API endpoint to process existing tally_snapshots data.
• Support filtering by org ID and/or product ID.
• Implement logic to identify the correct primary record per grouping logic for payg and non-payg.
• Ensure the operation is safe for re-runs and large datasets. Don't run anything yet on prod. Just enable the REST endpoint.

Acceptance Criteria

• REST endpoint is implemented and documented.
• Endpoint supports org ID and product ID as request parameters.
• Correct records are identified and updated with is_primary = true for payg and non-payg.
• Non-primary records are set or remain is_primary = false.
• Endpoint is idempotent and handles re-execution safely.
• No adverse impact on existing data or APIs.
• Component test to support this endpoint
• Don't run anything yet on prod. Just enable the REST endpoint.