Add a goose migration to create core and fedwiki schemas and move
existing
domain tables using ALTER TABLE IF EXISTS. Set connection search_path to
"core, public" after successful DB ping. Update FedWiki SQL and
sqlc.yaml to
use fedwiki.sites and include db migrations for schema awareness. Add
design
docs, specs, and tasks for schema-namespacing and the migration plan.
Add entitlement_sets and entitlement_set_rules with seed data and a
migration that backfills products, grants, and pool_provisions, then
removes product_entitlement_rules. Update Go models, sqlc queries,
materialization, and grant/provision flows to use entitlement_set_id.
Fix assembleMigrations to assign stable per-module numeric namespaces.
Move DB docs to docs/database-management.md and add design/specs/tests.
