Initial commit: AutonetSellCar platform with deployment system

- Frontend: Next.js 14 with TypeScript
- Backend: FastAPI with SQLAlchemy
- Agent: Carmodoo sync agent
- Deployment: Docker Compose based staging/production setup
- Scripts: Automated deployment with rollback support

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/add_exchange_rate_columns.py

@@ -0,0 +1,36 @@
+"""
+Add exchange rate weight columns to system_settings table
+"""
+import sqlite3
+
+def upgrade():
+    conn = sqlite3.connect('autonet.db')
+    cursor = conn.cursor()
+
+    # Check existing columns
+    cursor.execute("PRAGMA table_info(system_settings)")
+    columns = [col[1] for col in cursor.fetchall()]
+
+    new_columns = [
+        ('exchange_rate_weight_usd', 'FLOAT DEFAULT 0.0'),
+        ('exchange_rate_weight_mnt', 'FLOAT DEFAULT 0.0'),
+        ('exchange_rate_weight_rub', 'FLOAT DEFAULT 0.0'),
+        ('exchange_rate_weight_cny', 'FLOAT DEFAULT 0.0'),
+    ]
+
+    for col_name, col_type in new_columns:
+        if col_name not in columns:
+            try:
+                cursor.execute(f'ALTER TABLE system_settings ADD COLUMN {col_name} {col_type}')
+                print(f'Added column: {col_name}')
+            except Exception as e:
+                print(f'Error adding {col_name}: {e}')
+        else:
+            print(f'Column {col_name} already exists')
+
+    conn.commit()
+    conn.close()
+    print('Database migration complete!')
+
+if __name__ == '__main__':
+    upgrade()