Currently, the last used lineage context (org_id, merchant_id, profile_id, role_id, tenant_id) is cached temporarily in Redis with a 7-day TTL.
While this improves user experience across sessions, it introduces problems like:

• Redis is volatile — lineage context is lost if redis crashes
• Users switching between v1/v2 deployments have inconsistent Redis prefixes, leading to stale context (this has been fixed)
• Adds unnecessary dependency on Redis for critical authentication flow.

Objectives:

• Move the lineage context storage from Redis to the database (preferably to the users table as a new column).
• Ensure lineage context is persistently stored and updated in DB.

Tasks:

• Add a new nullable last_used_lineage_context (JSON/JSONB) column to the users table.

• Modify lineage context get and set helpers to use the DB instead of Redis.