feat(ingestion/dbt): add support for ingesting DBT contracts as Data Contracts

[ppiont]

Summary

Add support for ingesting DBT model contracts (introduced in dbt 1.5) as DataHub Data Contract entities with schema and data quality assertions.

Closes #11927

What problem does this solve?

DBT introduced model contracts in v1.5, allowing teams to define and enforce schema guarantees on models. However, DataHub had no way to ingest this contract metadata - it was lost during ingestion, and users couldn't see which models had contractual guarantees.

This PR bridges DBT's data governance (contracts) with DataHub's data governance (Data Contracts, Assertions), giving teams a unified view of their data quality guarantees.

What changes are being made?

New Configuration Options

Option	Default	Description
ingest_contracts	false	Enable Data Contract creation from DBT contracts
contract_test_tag	"contract"	Tag for tests to include in contract
ingest_column_constraints_as_assertions	true	Create assertions from not_null, unique, primary_key constraints

New Data Structures

• DBTContract dataclass - captures enforced, alias_types, checksum from manifest
• DBTConstraint dataclass - captures column/model-level constraints (not_null, unique, primary_key, etc.)

Contract Ingestion Flow

When ingest_contracts: true and a model has contract.enforced: true:

1. Schema Assertion - Created from contracted model columns with exact match compatibility
2. Constraint Assertions (optional) - Created for not_null, unique, primary_key constraints
3. Tagged Test Assertions - Existing DBT tests tagged with contract_test_tag are linked
4. Data Contract Entity - Bundles all assertions into a DataContractPropertiesClass

Platform Support

Platform	Contract Support	Notes
dbt Core	Full	Extracts from manifest.json
dbt Cloud	Best-effort	Reads from meta.contract or meta.datahub_contract (API doesn't expose contracts directly)

How was this tested?

• Added unit tests for new dataclasses (DBTContract, DBTConstraint)
• Added unit tests for configuration options
• Added integration test for contract extraction from manifest
• Tested locally with sample manifests containing contract.enforced: true

Checklist

• [x] The PR conforms to DataHub's Contributing Guideline
• [x] Links to related issues (Closes #11927)
• [x] Tests for the changes have been added
• [x] Docs have been added/updated (if needed - docs PR can follow)

Screenshots/Demo

After ingestion with ingest_contracts: true, models with contract.enforced: true will have:

• A Data Contract entity linked to the dataset
• Schema assertions validating the contracted columns
• (Optionally) Constraint assertions for not_null/unique/primary_key

[codecov[bot]]

Bundle Report

Changes will decrease total bundle size by 14.13kB (-0.05%) :arrow_down:. This is within the configured threshold :white_check_mark:

Detailed changes

Bundle name	Size	Change
datahub-react-web-esm	28.7MB	-14.13kB (-0.05%) :arrow_down:

Affected Assets, Files, and Routes:

view changes for bundle: datahub-react-web-esm

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
assets/index-*.js	-14.13kB	19.08MB	-0.07%

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests.

:loudspeaker: Thoughts on this report? Let us know!

[deepgarg760]

@ppiont Thanks for the contribution. Will take a look at this

[deepgarg760]

@ppiont , Please take care of prettier and linting errors

[deepgarg760]

@ppiont , any benchmark has been done regarding this ? like ingesting large number of DBT contracts