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/plugin-registry/tests/test_unit_plugin_registry.py

@@ -0,0 +1,101 @@
+"""Unit tests for plugin registry service"""
+
+import pytest
+import sys
+import sys
+from pathlib import Path
+from datetime import datetime
+
+
+from main import app, PluginRegistration, PluginVersion, SecurityScan
+
+
+@pytest.mark.unit
+def test_app_initialization():
+    """Test that the FastAPI app initializes correctly"""
+    assert app is not None
+    assert app.title == "AITBC Plugin Registry"
+    assert app.version == "1.0.0"
+
+
+@pytest.mark.unit
+def test_plugin_registration_model():
+    """Test PluginRegistration model"""
+    plugin = PluginRegistration(
+        name="Test Plugin",
+        version="1.0.0",
+        description="A test plugin",
+        author="Test Author",
+        category="testing",
+        tags=["test", "demo"],
+        repository_url="https://github.com/test/plugin",
+        homepage_url="https://test.com",
+        license="MIT",
+        dependencies=["dependency1"],
+        aitbc_version="1.0.0",
+        plugin_type="cli"
+    )
+    assert plugin.name == "Test Plugin"
+    assert plugin.version == "1.0.0"
+    assert plugin.author == "Test Author"
+    assert plugin.category == "testing"
+    assert plugin.tags == ["test", "demo"]
+    assert plugin.license == "MIT"
+    assert plugin.plugin_type == "cli"
+
+
+@pytest.mark.unit
+def test_plugin_registration_defaults():
+    """Test PluginRegistration default values"""
+    plugin = PluginRegistration(
+        name="Test Plugin",
+        version="1.0.0",
+        description="A test plugin",
+        author="Test Author",
+        category="testing",
+        tags=[],
+        repository_url="https://github.com/test/plugin",
+        license="MIT",
+        aitbc_version="1.0.0",
+        plugin_type="cli"
+    )
+    assert plugin.homepage_url is None
+    assert plugin.dependencies == []
+
+
+@pytest.mark.unit
+def test_plugin_version_model():
+    """Test PluginVersion model"""
+    version = PluginVersion(
+        version="1.0.0",
+        changelog="Initial release",
+        download_url="https://github.com/test/plugin/archive/v1.0.0.tar.gz",
+        checksum="abc123",
+        aitbc_compatibility=["1.0.0", "1.1.0"],
+        release_date=datetime.utcnow()
+    )
+    assert version.version == "1.0.0"
+    assert version.changelog == "Initial release"
+    assert version.download_url == "https://github.com/test/plugin/archive/v1.0.0.tar.gz"
+    assert version.checksum == "abc123"
+    assert version.aitbc_compatibility == ["1.0.0", "1.1.0"]
+
+
+@pytest.mark.unit
+def test_security_scan_model():
+    """Test SecurityScan model"""
+    scan = SecurityScan(
+        scan_id="scan_123",
+        plugin_id="test_plugin",
+        version="1.0.0",
+        scan_date=datetime.utcnow(),
+        vulnerabilities=[{"severity": "low", "description": "Test"}],
+        risk_score="low",
+        passed=True
+    )
+    assert scan.scan_id == "scan_123"
+    assert scan.plugin_id == "test_plugin"
+    assert scan.version == "1.0.0"
+    assert scan.risk_score == "low"
+    assert scan.passed is True
+    assert len(scan.vulnerabilities) == 1