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/src/database.py

@@ -1,5 +1,6 @@
 import asyncio
 import logging
+import os
 import subprocess
 
 from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
@@ -54,10 +55,10 @@ async def init_database(
             result = await asyncio.get_event_loop().run_in_executor(
                 None,
                 lambda: subprocess.run(
-                    ["alembic", "upgrade", "head"],
+                    ["python3", "-m", "alembic", "upgrade", "head"],
                     capture_output=True,
                     text=True,
-                    cwd="/app",
+                    cwd=os.path.dirname(os.path.dirname(os.path.abspath(__file__))),
                 ),
             )