style: apply black and isort formatting across entire codebase

- Standardize quote style (single to double quotes)
- Reorder and group imports alphabetically
- Fix line breaks and indentation for consistency
- Apply PEP 8 formatting standards

Also updated Makefile to exclude both venv and .venv from code quality checks.

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

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

alembic/env.py

@@ -15,6 +15,7 @@ import sys
 from logging.config import fileConfig
 
 from sqlalchemy import engine_from_config, pool
+
 from alembic import context
 
 # Add your project directory to the Python path
@@ -39,13 +40,9 @@ print("=" * 70)
 # ADMIN MODELS
 # ----------------------------------------------------------------------------
 try:
-    from models.database.admin import (
-        AdminAuditLog,
-        AdminNotification,
-        AdminSetting,
-        PlatformAlert,
-        AdminSession
-    )
+    from models.database.admin import (AdminAuditLog, AdminNotification,
+                                       AdminSession, AdminSetting,
+                                       PlatformAlert)
 
     print("  ✓ Admin models imported (5 models)")
     print("    - AdminAuditLog")
@@ -70,7 +67,7 @@ except ImportError as e:
 # VENDOR MODELS
 # ----------------------------------------------------------------------------
 try:
-    from models.database.vendor import Vendor, VendorUser, Role
+    from models.database.vendor import Role, Vendor, VendorUser
 
     print("  ✓ Vendor models imported (3 models)")
     print("    - Vendor")
@@ -248,10 +245,7 @@ def run_migrations_online() -> None:
     )
 
     with connectable.connect() as connection:
-        context.configure(
-            connection=connection,
-            target_metadata=target_metadata
-        )
+        context.configure(connection=connection, target_metadata=target_metadata)
 
         with context.begin_transaction():
             context.run_migrations()