[ElliotSun]

Tracks DaorynAI/semapact-project#127.

Summary

• add an opt-in live Databricks end-to-end smoke;
• prove candidate CREATE and ADD nullable-column convergence in a dedicated UAT schema;
• prove formal ContractRelease deployment, fresh IN_SYNC verification, and Unity Catalog provenance tags in a dedicated PROD schema;
• redeploy the exact release and require a fresh NO_OP/IN_SYNC result;
• keep the test skipped in normal CI;
• add a manually triggered protected GitHub Actions workflow;
• enforce dedicated semapact_smoke_* schemas and unique generated table names;
• document credentials, target configuration, safety boundaries, and cleanup.

The smoke uses the canonical application workflow and normal Databricks unified-auth boundary. It does not introduce a second deployment path.

Completion rule

Merging this PR installs the smoke framework only. Private roadmap issue #127 remains open until the workflow is executed successfully against a real Databricks workspace and the live CREATE / ADD COLUMN / release provenance / repeated NO_OP assertions all pass.