improvement(table): document that a column selection matching no column returns empty row data - #9915

Summary

• Clarifies the documented columns contract for row queries. A reference that matches no column is ignored, and if none match, each row's data is empty. The old wording ("a reference that matches no column is ignored") could be read as falling back to every column when nothing matches.
• No behavior change. Failing closed is intentional: widening a stale selection to every column would return cells the caller deliberately excluded. This behavior is already live for the v2 query API.
• The two row-query tools (table_query_rows, table_query_rows_v2) now share one TABLE_COLUMNS_PARAM in tools/table/params.ts, following TABLE_ID_PARAM, so their parameter descriptions can't drift apart. The contract description (rowColumnSelectionSchema) stays separate because it documents the API field.
• Regenerated tool-metadata.ts and the Table integration docs page.

Type of Change

• Documentation / improvement (no behavior change)

Testing

• Ran the table tool and internal table operation suites (tools/table, lib/internal/table, the table block tests, lib/api/contracts): all pass.
• Ran check:docs, check:api-validation:strict and check:comment-hygiene. The pre-push lint:check and type-check pass.

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing (new tests pass the test-audit authoring gate)
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)