Add sys import to test files and remove obsolete integration tests

- Add sys import to 29 test files across agent-coordinator, blockchain-event-bridge, blockchain-node, and coordinator-api
- Remove apps/blockchain-event-bridge/tests/test_integration.py (obsolete bridge integration tests)
- Remove apps/coordinator-api/tests/test_integration.py (obsolete API integration tests)
- Implement GPU registration in marketplace_gpu.py with GPURegistry model persistence

apps/exchange/tests/test_edge_cases_exchange.py

@@ -0,0 +1,142 @@
+"""Edge case and error handling tests for exchange service"""
+
+import pytest
+import sys
+import sys
+from pathlib import Path
+
+
+from exchange_api import OrderCreate, OrderResponse, TradeResponse, OrderBookResponse
+from datetime import datetime
+
+
+@pytest.mark.unit
+def test_order_create_empty_type():
+    """Test OrderCreate with empty order type"""
+    order = OrderCreate(
+        order_type="",
+        amount=100.0,
+        price=0.00001
+    )
+    assert order.order_type == ""
+
+
+@pytest.mark.unit
+def test_order_create_zero_amount():
+    """Test OrderCreate with zero amount"""
+    order = OrderCreate(
+        order_type="BUY",
+        amount=0.0,
+        price=0.00001
+    )
+    assert order.amount == 0.0
+
+
+@pytest.mark.unit
+def test_order_create_negative_price():
+    """Test OrderCreate with negative price"""
+    order = OrderCreate(
+        order_type="BUY",
+        amount=100.0,
+        price=-0.00001
+    )
+    assert order.price == -0.00001
+
+
+@pytest.mark.unit
+def test_order_response_zero_remaining():
+    """Test OrderResponse with zero remaining"""
+    order = OrderResponse(
+        id=1,
+        order_type="BUY",
+        amount=100.0,
+        price=0.00001,
+        total=0.001,
+        filled=100.0,
+        remaining=0.0,
+        status="FILLED",
+        created_at=datetime.utcnow()
+    )
+    assert order.remaining == 0.0
+    assert order.status == "FILLED"
+
+
+@pytest.mark.unit
+def test_order_response_empty_status():
+    """Test OrderResponse with empty status"""
+    order = OrderResponse(
+        id=1,
+        order_type="BUY",
+        amount=100.0,
+        price=0.00001,
+        total=0.001,
+        filled=0.0,
+        remaining=100.0,
+        status="",
+        created_at=datetime.utcnow()
+    )
+    assert order.status == ""
+
+
+@pytest.mark.unit
+def test_trade_response_zero_amount():
+    """Test TradeResponse with zero amount"""
+    trade = TradeResponse(
+        id=1,
+        amount=0.0,
+        price=0.00001,
+        total=0.0,
+        created_at=datetime.utcnow()
+    )
+    assert trade.amount == 0.0
+    assert trade.total == 0.0
+
+
+@pytest.mark.unit
+def test_order_book_empty_buys():
+    """Test OrderBookResponse with empty buys"""
+    orderbook = OrderBookResponse(buys=[], sells=[])
+    assert len(orderbook.buys) == 0
+    assert len(orderbook.sells) == 0
+
+
+@pytest.mark.unit
+def test_order_book_empty_sells():
+    """Test OrderBookResponse with empty sells"""
+    from datetime import datetime
+    buy_order = OrderResponse(
+        id=1,
+        order_type="BUY",
+        amount=100.0,
+        price=0.00001,
+        total=0.001,
+        filled=0.0,
+        remaining=100.0,
+        status="OPEN",
+        created_at=datetime.utcnow()
+    )
+    orderbook = OrderBookResponse(buys=[buy_order], sells=[])
+    assert len(orderbook.buys) == 1
+    assert len(orderbook.sells) == 0
+
+
+@pytest.mark.unit
+def test_order_create_very_large_amount():
+    """Test OrderCreate with very large amount"""
+    order = OrderCreate(
+        order_type="BUY",
+        amount=9999999999.0,
+        price=0.00001
+    )
+    assert order.amount == 9999999999.0
+
+
+@pytest.mark.unit
+def test_order_create_very_small_price():
+    """Test OrderCreate with very small price"""
+    order = OrderCreate(
+        order_type="BUY",
+        amount=100.0,
+        price=0.000000001
+    )
+    assert order.price == 0.000000001