#71 DB Migration: Sessions Table

Create database migration for sessions tracking table. Migration File: engine/migrations/sql/XXX_sessions_table.sql Table: sessions Columns: - id: uuid primary key - user_id: uuid (foreign key to users) - tenant_id: varchar(100) - token_hash: varchar(64) unique (SHA256 of JWT) - ip_address: inet - user_agent: text - created_at: timestamp - last_activity_at: timestamp - expires_at: timestamp - is_active: boolean default true - terminated_at: timestamp - terminated_by: uuid (foreign key to users) - termination_reason: varchar(100) Indexes: - idx_sessions_user_id - idx_sessions_tenant_active - idx_sessions_expires_at - idx_sessions_token_hash With ultra attention to details and correctness. Before closing: write comment summarizing implementation with screenshot.