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/models/organization.py

@@ -1,5 +1,5 @@
 # app/models/organization.py
-from sqlalchemy import Column, String, Boolean, Text, Index
+from sqlalchemy import Boolean, Column, Index, String, Text
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.orm import relationship
 
@@ -11,7 +11,8 @@ class Organization(Base, UUIDMixin, TimestampMixin):
     Organization model for multi-tenant support.
     Users can belong to multiple organizations with different roles.
     """
-    __tablename__ = 'organizations'
+
+    __tablename__ = "organizations"
 
     name = Column(String(255), nullable=False, index=True)
     slug = Column(String(255), unique=True, nullable=False, index=True)
@@ -20,11 +21,13 @@ class Organization(Base, UUIDMixin, TimestampMixin):
     settings = Column(JSONB, default={})
 
     # Relationships
-    user_organizations = relationship("UserOrganization", back_populates="organization", cascade="all, delete-orphan")
+    user_organizations = relationship(
+        "UserOrganization", back_populates="organization", cascade="all, delete-orphan"
+    )
 
     __table_args__ = (
-        Index('ix_organizations_name_active', 'name', 'is_active'),
-        Index('ix_organizations_slug_active', 'slug', 'is_active'),
+        Index("ix_organizations_name_active", "name", "is_active"),
+        Index("ix_organizations_slug_active", "slug", "is_active"),
     )
 
     def __repr__(self):