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>

scripts/verify_setup.py

@@ -5,10 +5,10 @@ import os
 import sys
 from urllib.parse import urlparse
 
+from alembic.config import Config
 from sqlalchemy import create_engine, text
 
 from alembic import command
-from alembic.config import Config
 
 # Add project root to Python path
 sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
@@ -28,8 +28,7 @@ def get_database_info():
         if db_path.startswith("./"):
             db_path = db_path[2:]
         return db_type, db_path
-    else:
-        return db_type, None
+    return db_type, None
 
 
 def verify_database_setup():
@@ -138,7 +137,7 @@ def verify_model_structure():
     try:
         from models.database.base import Base
 
-        print(f"[OK] Database Base imported")
+        print("[OK] Database Base imported")
         print(
             f"[INFO] Found {len(Base.metadata.tables)} database tables: {list(Base.metadata.tables.keys())}"
         )
@@ -191,7 +190,7 @@ def verify_model_structure():
 def check_project_structure():
     """Check overall project structure."""
 
-    print(f"\n[STRUCTURE] Checking project structure...")
+    print("\n[STRUCTURE] Checking project structure...")
 
     critical_paths = [
         "models/database/base.py",
@@ -216,7 +215,7 @@ def check_project_structure():
         "models/api/__init__.py",
     ]
 
-    print(f"\n[INIT] Checking __init__.py files...")
+    print("\n[INIT] Checking __init__.py files...")
     for init_file in init_files:
         if os.path.exists(init_file):
             print(f"    * {init_file}")