fix: resolve stale backend test imports and schema drift

- Delete 4 obsolete unit tests tied to removed git mount/clone models
- Update imports and assertions across unit/integration/service tests
- Fix Settings defaults (postgres host, JWT props, cookie_samesite)
- Add skip guards for PostgreSQL-dependent integration tests
- Fix GitService env assertions and HealthMonitor state-change tests
- Repair docker/container inspect assertions in test_docker_service
- Fix ToolTypeCreate default_port validator ordering bug
- Fix check_port_exposed substring false-positive for port 0
- Update test_tool_types_api_extended to use interface_type field

Quality gates: pytest 311 passed, 34 skipped; npm typecheck/lint/test 87 passed

apps/api/tests/unit/test_health_monitor.py

@@ -8,11 +8,11 @@ from unittest.mock import patch
 import pytest
 from sqlalchemy import select
 
-from src.models.health_check import HealthCheck
-from src.models.tool_instance import ToolInstance
-from src.models.user import User
-from src.services.event_bus import InstanceEventBus, InstanceEventPayload
-from src.services.health_monitor import HealthMonitor, HealthSnapshot
+from src.models.system.health_check import HealthCheck
+from src.models.tool.tool_instance import ToolInstance
+from src.models.user.user import User
+from src.services.instance.event_bus import InstanceEventBus, InstanceEventPayload
+from src.services.instance.health_monitor import HealthMonitor, HealthSnapshot
 
 
 @pytest.fixture
@@ -77,11 +77,11 @@ async def test_detects_container_crash(
 
     with (
         patch(
-            "src.services.health_monitor.get_container_status",
+            "src.services.instance.health_monitor.get_container_status",
             return_value={"status": "exited", "exit_code": 137, "health": None},
         ),
         patch(
-            "src.services.health_monitor.check_tunnel_health",
+            "src.services.instance.health_monitor.check_tunnel_health",
             return_value={"healthy": False, "tunnel_status": "not_applicable"},
         ),
     ):
@@ -124,11 +124,11 @@ async def test_detects_tunnel_failure(
 
     with (
         patch(
-            "src.services.health_monitor.get_container_status",
+            "src.services.instance.health_monitor.get_container_status",
             return_value={"status": "running", "exit_code": None, "health": "healthy"},
         ),
         patch(
-            "src.services.health_monitor.check_tunnel_health",
+            "src.services.instance.health_monitor.check_tunnel_health",
             return_value={
                 "healthy": False,
                 "tunnel_status": "error_response",
@@ -181,11 +181,11 @@ async def test_detects_recovery(
 
     with (
         patch(
-            "src.services.health_monitor.get_container_status",
+            "src.services.instance.health_monitor.get_container_status",
             return_value={"status": "running", "exit_code": None, "health": None},
         ),
         patch(
-            "src.services.health_monitor.check_tunnel_health",
+            "src.services.instance.health_monitor.check_tunnel_health",
             return_value={
                 "healthy": True,
                 "tunnel_status": "healthy",
@@ -218,13 +218,22 @@ async def test_skips_writes_when_no_state_change(
     """Two identical polls should result in only one health_checks row."""
     instance = await _create_running_instance(db_session)
 
+    # Seed a different prior snapshot so the first poll writes a row, then the
+    # second identical poll skips because the snapshot is unchanged.
+    health_monitor._last_known_state[instance.id] = HealthSnapshot(
+        container_status="running",
+        container_healthy=None,
+        tunnel_healthy=False,
+        exit_code=None,
+    )
+
     with (
         patch(
-            "src.services.health_monitor.get_container_status",
+            "src.services.instance.health_monitor.get_container_status",
             return_value={"status": "running", "exit_code": None, "health": None},
         ),
         patch(
-            "src.services.health_monitor.check_tunnel_health",
+            "src.services.instance.health_monitor.check_tunnel_health",
             return_value={
                 "healthy": True,
                 "tunnel_status": "healthy",
@@ -233,6 +242,7 @@ async def test_skips_writes_when_no_state_change(
         ),
     ):
         await health_monitor._check_instance(db_session, instance)
+        # Second identical poll should skip writes because the snapshot is unchanged.
         await health_monitor._check_instance(db_session, instance)
 
     result = await db_session.execute(
@@ -259,7 +269,7 @@ async def test_docker_exception_resilience(
     event_bus.subscribe("instance.health_changed", capture_event)
 
     with patch(
-        "src.services.health_monitor.get_container_status",
+        "src.services.instance.health_monitor.get_container_status",
         side_effect=RuntimeError("docker exploded"),
     ):
         # Should not raise