feat: switch to persistent SQLite database and improve GPU booking/release handling

- Change database from in-memory to file-based SQLite at aitbc_coordinator.db
- Add status="active" to GPU booking creation
- Allow GPU release even when not properly booked (cleanup case)
- Add error handling for missing booking attributes during refund calculation
- Fix get_gpu_reviews query to use scalars() for proper result handling

scripts/cleanup_fake_gpus_db.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+"""
+Direct database cleanup for fake GPU entries
+"""
+
+import sys
+import os
+sys.path.insert(0, '/home/oib/windsurf/aitbc/apps/coordinator-api/src')
+
+from sqlmodel import Session, select
+from app.database import engine, create_db_and_tables
+from app.domain.gpu_marketplace import GPURegistry
+
+def cleanup_fake_gpus():
+    """Clean up fake GPU entries from database"""
+    print("=== DIRECT DATABASE CLEANUP ===")
+    
+    # Create tables if they don't exist
+    create_db_and_tables()
+    
+    fake_gpus = [
+        "gpu_1bdf8e86",
+        "gpu_1b7da9e0", 
+        "gpu_9cff5bc2",
+        "gpu_ebef80a5",
+        "gpu_979b24b8",
+        "gpu_e5ab817d"
+    ]
+    
+    with Session(engine) as session:
+        deleted_count = 0
+        
+        for gpu_id in fake_gpus:
+            gpu = session.exec(select(GPURegistry).where(GPURegistry.id == gpu_id)).first()
+            if gpu:
+                print(f"🗑️  Deleting fake GPU: {gpu_id} - {gpu.model}")
+                session.delete(gpu)
+                deleted_count += 1
+            else:
+                print(f"❓ GPU not found: {gpu_id}")
+        
+        try:
+            session.commit()
+            print(f"✅ Successfully deleted {deleted_count} fake GPUs")
+        except Exception as e:
+            print(f"❌ Error committing changes: {e}")
+            session.rollback()
+            return False
+    
+    return True
+
+def show_remaining_gpus():
+    """Show remaining GPUs after cleanup"""
+    print("\n📋 Remaining GPUs in marketplace:")
+    
+    with Session(engine) as session:
+        gpus = session.exec(select(GPURegistry)).all()
+        
+        if gpus:
+            for gpu in gpus:
+                print(f"  🎮 {gpu.id}: {gpu.model} - {gpu.status} - {gpu.price_per_hour} AITBC/hr")
+        else:
+            print("  No GPUs found")
+    
+    return len(gpus)
+
+if __name__ == "__main__":
+    if cleanup_fake_gpus():
+        remaining = show_remaining_gpus()
+        print(f"\n🎉 Cleanup complete! {remaining} GPUs remaining in marketplace")
+    else:
+        print("\n❌ Cleanup failed!")
+        sys.exit(1)