feat: add artefact.attributes JSONB column (expand) [1/3]

[almeidaraul]

Part 1 of 3 (stacked) — splitting TO-404/remove-solution-specific-fields into rolling-upgrade-safe expand/contract steps.

What

Expand step: introduce a generic attributes JSONB field on artefacts, without changing any behaviour.

• Add the attributes column via a non-destructive migration (add column only, empty-object default).
• Map attributes on the Artefact ORM model and expose it read-only on ArtefactResponse.
• All existing solution-specific fields/mappings are left untouched, so old code keeps working during a rolling upgrade.
• Normalise integer-valued floats when fetching the OpenAPI schema so the committed schema is stable across jq versions in CI.

Safety

No-op for clients: nothing writes to or reads from attributes yet.

Stacked PR order

1. This PR → main
2. TO-404/2-write-both → TO-404/1-add-attributes
3. TO-404/3-migrate-read-new → TO-404/2-write-both

Each must be merged and deployed before the next (expand/contract rolling-upgrade requirement).

[Copilot]

Pull request overview

Implements the expand step of a rolling-upgrade-safe migration to introduce a generic artefact.attributes JSONB column, exposing it read-only via the API while keeping existing solution-specific fields untouched.

Changes:

• Add artefact.attributes JSONB column with an empty-object default via Alembic (non-destructive expand migration).
• Map attributes on the SQLAlchemy Artefact model and include it in ArtefactResponse + controller expectations/tests.
• Stabilize committed OpenAPI schema diffs across CI by normalizing integer-valued floats in the schema fetch + compare steps.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
backend/migrations/versions/2026_08_17_1723-6e262c3c6c8f_add_artefact_attributes.py	Adds the attributes JSONB column with an empty default (expand step).
backend/test_observer/data_access/models.py	Maps Artefact.attributes as a mutable JSONB dict with defaults.
backend/test_observer/controllers/artefacts/models.py	Exposes attributes on the ArtefactResponse API model.
backend/tests/data_access/test_models.py	Adds persistence/default tests for Artefact.attributes.
backend/tests/controllers/artefacts/test_artefacts.py	Updates expected artefact controller response to include attributes.
backend/tests/controllers/test_executions/test_reruns.py	Updates expected rerun response payload to include attributes.
backend/scripts/fetch_openapi_schema.sh	Normalizes schema numbers for stable committed OpenAPI output.
backend/schemata/openapi.json	Updates committed OpenAPI schema to include attributes.
.github/workflows/test_backend.yml	Keeps CI schema comparison stable by applying the same jq normalization filter.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.