Migrate from declarative_base to DeclarativeBase and improve type safety

[Copilot]

This PR migrates DiracX from the old-style SQLAlchemy declarative_base() function to the new-style DeclarativeBase class, following SQLAlchemy 2.0+ best practices and improving type safety throughout the codebase.

Key Changes

Before:

from sqlalchemy.orm import declarative_base
Base = declarative_base()

# Type hints using Any
async def _search(self, table: Any, ...):

After:

from sqlalchemy.orm import DeclarativeBase

class Base(DeclarativeBase):
    pass

# Proper type hints
async def _search(self, table: type[DeclarativeBase], ...):

Benefits

• Enhanced Type Safety: Replaced Any type hints in _search and _summary methods with proper type[DeclarativeBase] annotations
• Better IDE Support: Improved autocompletion and type checking for database models
• Modern SQLAlchemy: Uses SQLAlchemy 2.0+ recommended patterns
• Developer Experience: Type checkers (mypy/pyright) can now catch type errors at development time

Files Modified

• 7 core schema files: Migrated all database schema base classes
• 1 utils file: Improved type annotations for search methods
• 2 extension files: Updated to use proper imports and DeclarativeBase

All changes are backward compatible with zero breaking changes to the existing API.

Fixes #612.

---

💬 Share your feedback on Copilot coding agent for the chance to win a $200 gift card! Click here to start the survey.

[chrisburr]

@copilot Pre-commit is failing:

diracx-db/src/diracx/db/sql/utils/base.py:287: error: "Iterable[NamedColumn[Any]]" has no attribute "columns"  [attr-defined]
diracx-db/src/diracx/db/sql/task_queue/db.py:150: note: By default the bodies of untyped functions are not checked, consider using --check-untyped-defs  [annotation-unchecked]
diracx-db/src/diracx/db/sql/job_logging/db.py:59: error: "FromClause" has no attribute "insert"  [attr-defined]
diracx-db/src/diracx/db/sql/job/db.py:76: error: "FromClause" has no attribute "insert"  [attr-defined]
diracx-db/src/diracx/db/sql/job/db.py:92: error: "FromClause" has no attribute "insert"  [attr-defined]
diracx-db/src/diracx/db/sql/job/db.py:106: error: "FromClause" has no attribute "insert"  [attr-defined]
diracx-db/src/diracx/db/sql/job/db.py:119: error: "FromClause" has no attribute "update"  [attr-defined]
diracx-db/src/diracx/db/sql/job/db.py:270: error: "FromClause" has no attribute "insert"  [attr-defined]
diracx-routers/src/diracx/routers/factory.py:531: note: By default the bodies of untyped functions are not checked, consider using --check-untyped-defs  [annotation-unchecked]
diracx-routers/src/diracx/routers/factory.py:533: note: By default the bodies of untyped functions are not checked, consider using --check-untyped-defs  [annotation-unchecked]
Found 7 errors in 3 files (checked 161 source files)

You should use pixi run pre-commit --all-files to verify your changes.

[Copilot]

@copilot Pre-commit is failing:

...

Fixed the pre-commit type checking errors. The issues were caused by the migration to DeclarativeBase requiring more specific type annotations:

• Added proper Table import and cast operations for __table__ attributes
• Fixed _get_columns function parameter types
• Used cast("Table", SomeModel.__table__) to help mypy understand table operations

All the attr-defined errors are now resolved (commit 0c4f83a).