Add pyproject.toml for consolidated project configuration and replace Black, isort, and Flake8 with Ruff

- Introduced `pyproject.toml` to centralize backend tool configurations (e.g., Ruff, mypy, coverage, pytest).
- Replaced Black, isort, and Flake8 with Ruff for linting, formatting, and import sorting.
- Updated `requirements.txt` to include Ruff and remove replaced tools.
- Added `Makefile` to streamline development workflows with commands for linting, formatting, type-checking, testing, and cleanup.

backend/app/alembic/versions/b76c725fc3cf_add_composite_indexes.py

@@ -5,17 +5,17 @@ Revises: 2d0fcec3b06d
 Create Date: 2025-10-30 16:41:33.273135
 
 """
-from typing import Sequence, Union
+
+from collections.abc import Sequence
 
 import sqlalchemy as sa
-
 from alembic import op
 
 # revision identifiers, used by Alembic.
-revision: str = 'b76c725fc3cf'
-down_revision: Union[str, None] = '2d0fcec3b06d'
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
+revision: str = "b76c725fc3cf"
+down_revision: str | None = "2d0fcec3b06d"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
 
 
 def upgrade() -> None:
@@ -23,30 +23,26 @@ def upgrade() -> None:
 
     # Composite index for filtering active users by role
     op.create_index(
-        'ix_users_active_superuser',
-        'users',
-        ['is_active', 'is_superuser'],
-        postgresql_where=sa.text('deleted_at IS NULL')
+        "ix_users_active_superuser",
+        "users",
+        ["is_active", "is_superuser"],
+        postgresql_where=sa.text("deleted_at IS NULL"),
     )
 
     # Composite index for sorting active users by creation date
     op.create_index(
-        'ix_users_active_created',
-        'users',
-        ['is_active', 'created_at'],
-        postgresql_where=sa.text('deleted_at IS NULL')
+        "ix_users_active_created",
+        "users",
+        ["is_active", "created_at"],
+        postgresql_where=sa.text("deleted_at IS NULL"),
     )
 
     # Composite index for email lookup of non-deleted users
-    op.create_index(
-        'ix_users_email_not_deleted',
-        'users',
-        ['email', 'deleted_at']
-    )
+    op.create_index("ix_users_email_not_deleted", "users", ["email", "deleted_at"])
 
 
 def downgrade() -> None:
     # Remove composite indexes
-    op.drop_index('ix_users_email_not_deleted', table_name='users')
-    op.drop_index('ix_users_active_created', table_name='users')
-    op.drop_index('ix_users_active_superuser', table_name='users')
+    op.drop_index("ix_users_email_not_deleted", table_name="users")
+    op.drop_index("ix_users_active_created", table_name="users")
+    op.drop_index("ix_users_active_superuser", table_name="users")