feat(setup): T01 create project directory structure

- Create src/openrouter_monitor/ package structure
- Create models/, routers/, services/, utils/ subpackages
- Create tests/unit/ and tests/integration/ structure
- Create alembic/, docs/, scripts/ directories
- Add test_project_structure.py with 13 unit tests
- All tests passing (13/13)

Refs: T01

tests/unit/test_project_structure.py

@@ -0,0 +1,90 @@
+"""Test for project structure setup (T01)."""
+import os
+import pytest
+
+
+@pytest.mark.unit
+class TestProjectStructure:
+    """Test project directory structure is correctly created."""
+    
+    def test_src_directory_exists(self):
+        """Verify src/openrouter_monitor/ directory exists."""
+        src_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/src/openrouter_monitor"
+        assert os.path.isdir(src_path), f"Directory {src_path} does not exist"
+    
+    def test_src_init_file_exists(self):
+        """Verify src/openrouter_monitor/__init__.py exists."""
+        init_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/src/openrouter_monitor/__init__.py"
+        assert os.path.isfile(init_path), f"File {init_path} does not exist"
+    
+    def test_main_py_exists(self):
+        """Verify main.py exists in src."""
+        main_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/src/openrouter_monitor/main.py"
+        assert os.path.isfile(main_path), f"File {main_path} does not exist"
+    
+    def test_config_py_exists(self):
+        """Verify config.py exists in src."""
+        config_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/src/openrouter_monitor/config.py"
+        assert os.path.isfile(config_path), f"File {config_path} does not exist"
+    
+    def test_database_py_exists(self):
+        """Verify database.py exists in src."""
+        db_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/src/openrouter_monitor/database.py"
+        assert os.path.isfile(db_path), f"File {db_path} does not exist"
+    
+    def test_models_directory_exists(self):
+        """Verify models/ directory exists with __init__.py."""
+        models_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/src/openrouter_monitor/models"
+        init_path = os.path.join(models_path, "__init__.py")
+        assert os.path.isdir(models_path), f"Directory {models_path} does not exist"
+        assert os.path.isfile(init_path), f"File {init_path} does not exist"
+    
+    def test_routers_directory_exists(self):
+        """Verify routers/ directory exists with __init__.py."""
+        routers_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/src/openrouter_monitor/routers"
+        init_path = os.path.join(routers_path, "__init__.py")
+        assert os.path.isdir(routers_path), f"Directory {routers_path} does not exist"
+        assert os.path.isfile(init_path), f"File {init_path} does not exist"
+    
+    def test_services_directory_exists(self):
+        """Verify services/ directory exists with __init__.py."""
+        services_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/src/openrouter_monitor/services"
+        init_path = os.path.join(services_path, "__init__.py")
+        assert os.path.isdir(services_path), f"Directory {services_path} does not exist"
+        assert os.path.isfile(init_path), f"File {init_path} does not exist"
+    
+    def test_utils_directory_exists(self):
+        """Verify utils/ directory exists with __init__.py."""
+        utils_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/src/openrouter_monitor/utils"
+        init_path = os.path.join(utils_path, "__init__.py")
+        assert os.path.isdir(utils_path), f"Directory {utils_path} does not exist"
+        assert os.path.isfile(init_path), f"File {init_path} does not exist"
+    
+    def test_tests_directory_structure(self):
+        """Verify tests/ directory structure exists."""
+        tests_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/tests"
+        unit_path = os.path.join(tests_path, "unit")
+        integration_path = os.path.join(tests_path, "integration")
+        conftest_path = os.path.join(tests_path, "conftest.py")
+        
+        assert os.path.isdir(tests_path), f"Directory {tests_path} does not exist"
+        assert os.path.isdir(unit_path), f"Directory {unit_path} does not exist"
+        assert os.path.isfile(os.path.join(unit_path, "__init__.py")), f"unit/__init__.py does not exist"
+        assert os.path.isdir(integration_path), f"Directory {integration_path} does not exist"
+        assert os.path.isfile(os.path.join(integration_path, "__init__.py")), f"integration/__init__.py does not exist"
+        assert os.path.isfile(conftest_path), f"File {conftest_path} does not exist"
+    
+    def test_alembic_directory_exists(self):
+        """Verify alembic/ directory exists."""
+        alembic_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/alembic"
+        assert os.path.isdir(alembic_path), f"Directory {alembic_path} does not exist"
+    
+    def test_docs_directory_exists(self):
+        """Verify docs/ directory exists."""
+        docs_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/docs"
+        assert os.path.isdir(docs_path), f"Directory {docs_path} does not exist"
+    
+    def test_scripts_directory_exists(self):
+        """Verify scripts/ directory exists."""
+        scripts_path = "/home/google/Sources/LucaSacchiNet/openrouter-watcher/scripts"
+        assert os.path.isdir(scripts_path), f"Directory {scripts_path} does not exist"