Define uuid_generate_v7() in the first migration and switch all table
primary key defaults to it. Remove the uuid-ossp extension dependency.
Update refresh token and request ID generation in Go code to use
uuid.NewV7() from the existing google/uuid v1.6.0 library.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
TIMESTAMPTZ + INTERVAL is STABLE (depends on timezone), not IMMUTABLE,
so PostgreSQL rejects it in GENERATED ALWAYS AS STORED columns.
Fix: remove generated column and compute expires_at inline in each query
as (added_at + storage_days * INTERVAL '1 day').
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>