fix(db): import declarative_base/declared_attr from sqlalchemy.orm (ext.declarative is deprecated)

[jdmanring]

Problem

core/database.py imports from the legacy sqlalchemy.ext.declarative location:

from sqlalchemy.ext.declarative import declarative_base, declared_attr

On SQLAlchemy 2.0 this emits a MovedIn20Warning on every import of core.database:

MovedIn20Warning: The declarative_base() function is now available as sqlalchemy.orm.declarative_base(). (deprecated since: 2.0)

Fix

Both names are re-exported from sqlalchemy.orm (verified on 2.0.50):

from sqlalchemy.orm import declarative_base, declared_attr

No behavioral change — same objects, current import path, warning gone.

Notes

• upstream-candidate: the deprecated import is upstream-inherited (present in upstream-mirror), touched by no other staged branch.
• Sibling to the SQLAlchemy-family deprecation fix already staged as fix(auth): api-token last_used_at uses deprecated datetime.utcnow() instead of utcnow_naive() #51 (utcnow); handled the same way — its own single-commit PR.

[github-actions]

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