Search Table Inventory Api

Name-searchable table inventory, read from table_metadata (AI-8314).

The Studio opportunity picker used /tabledata, a Snowflake cost rollup that lists strictly fewer tables than the publish gate accepts — 1,253 of 2,920 on prod megatenant, and nothing at all on a new-pipeline tenant. This reads the same table the gate verifies against, so anything listed here can be published, and it searches server-side rather than filtering one already-fetched page.