refactor: modernize code quality tooling with Ruff

- Replace black, isort, and flake8 with Ruff (all-in-one linter and formatter)
- Add comprehensive pyproject.toml configuration
- Simplify Makefile code quality targets
- Configure exclusions for venv/.venv in pyproject.toml
- Auto-fix 1,359 linting issues across codebase

Benefits:
- Much faster builds (Ruff is written in Rust)
- Single tool replaces multiple tools
- More comprehensive rule set (UP, B, C4, SIM, PIE, RET, Q)
- All configuration centralized in pyproject.toml
- Better import sorting and formatting consistency

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

models/database/__init__.py

@@ -1,7 +1,13 @@
 # models/database/__init__.py
 """Database models package."""
-from .admin import (AdminAuditLog, AdminNotification, AdminSession,
-                    AdminSetting, PlatformAlert)
+
+from .admin import (
+    AdminAuditLog,
+    AdminNotification,
+    AdminSession,
+    AdminSetting,
+    PlatformAlert,
+)
 from .base import Base
 from .customer import Customer, CustomerAddress
 from .inventory import Inventory