feat(input-mapping): AJDA-2714 read description from table definition

[odinuv]

Link to issue

https://linear.app/keboola/issue/AJDA-2714/input-mapping-read-description-primarily-from-table-definition

Description

Input Mapping now exposes the table/column description from the native first-class definition field in the table manifest, and adds a new first-class schema node mirroring the output-mapping schema shape.

ManifestCreator::writeTableManifest adds two native-sourced fields (purely additive — the legacy columns/column_metadata/metadata structures are left untouched):

• description (top-level): taken from definition.description; omitted when absent/empty.
• schema: one entry per selected column with name, data_type (base + the table's actual backend type, including length/default when present), nullable, primary_key, and the native description. Emitted for both typed and non-typed tables (non-typed columns simply omit data_type/nullable); a table with no definition serializes an empty schema: [].

Key decisions:

• Native is the only source for the new fields. Description fallback is not resolved by Input Mapping — the legacy KBC.description metadata is left intact and Connection backfills the native description into it, so consumers without native support keep working. This also avoids having to pick a winner among multiple multi-provider KBC.description records.
• No schema[].metadata — it would require collapsing multiple metadata records into a single map (lossy/ambiguous). Raw records stay in the untouched column_metadata.
• Single backend — data_type reflects the table's actual backend only (base + that one backend), matching the real state of the table.

Justification

Native description is now a first-class field on table/column definitions in Storage. See the linked Linear issue.

Plans for Customer Communication

None.

Impact Analysis

Additive change to the table manifest only (new description and schema keys; every manifest now also carries schema, empty when there is no definition). No existing manifest fields change, so current consumers are unaffected. Not gated by a feature flag.

Deployment Plan

Release a tagged version.

Rollback Plan

Revert this PR.

Post-Release Support Plan

None.

[linear]

AJDA-2714

[odinuv]

@kudj Chystaná změna input manifestu na komponentě - kvůli přidání description, současně přidává i schema v co nejpodobnějším tvaru jako je na output mappingu.

[zajca]

Přijde mě to cajk nenapadá mě kde by to mohlo zhučat, necháme sa překvapit.

[soustruh]

LGTM ദ്ദി(•ᴗ•)