feat: Enhance dashboard metrics and summary statistics

- Added new summary fields: variance, 5th percentile, 95th percentile, VaR (95%), and expected shortfall (95%) to the dashboard.
- Updated the display logic for summary metrics to handle non-finite values gracefully.
- Modified the chart rendering to include additional percentile points and tail risk metrics in tooltips.

test: Introduce unit tests for consumption, costs, and other modules

- Created a comprehensive test suite for consumption, costs, equipment, maintenance, production, reporting, and simulation modules.
- Implemented fixtures for database setup and teardown using an in-memory SQLite database for isolated testing.
- Added tests for creating, listing, and validating various entities, ensuring proper error handling and response validation.

refactor: Consolidate parameter tests and remove deprecated files

- Merged parameter-related tests into a new test file for better organization and clarity.
- Removed the old parameter test file that was no longer in use.
- Improved test coverage for parameter creation, listing, and validation scenarios.

fix: Ensure proper validation and error handling in API endpoints

- Added validation to reject negative amounts in consumption and production records.
- Implemented checks to prevent duplicate scenario creation and ensure proper error messages are returned.
- Enhanced reporting endpoint tests to validate input formats and expected outputs.

tests/unit/test_simulation.py

@@ -1,42 +1,111 @@
-from services.simulation import run_simulation
-from main import app
-from config.database import Base, engine
-from fastapi.testclient import TestClient
+from uuid import uuid4
+
 import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy.orm import Session
 
-# Setup and teardown
+from models.simulation_result import SimulationResult
+from services.simulation import run_simulation
 
 
-def setup_module(module):
-    Base.metadata.create_all(bind=engine)
+@pytest.fixture
+def client(api_client: TestClient) -> TestClient:
+    return api_client
 
 
-def teardown_module(module):
-    Base.metadata.drop_all(bind=engine)
-
-
-client = TestClient(app)
-
-# Direct function test
-
-
-def test_run_simulation_function_returns_list():
-    results = run_simulation([], iterations=10)
+def test_run_simulation_function_generates_samples():
+    params = [
+        {"name": "grade", "value": 1.8, "distribution": "normal", "std_dev": 0.2},
+        {
+            "name": "recovery",
+            "value": 0.9,
+            "distribution": "uniform",
+            "min": 0.8,
+            "max": 0.95,
+        },
+    ]
+    results = run_simulation(params, iterations=5, seed=123)
     assert isinstance(results, list)
-    assert results == []
-
-# Endpoint tests
+    assert len(results) == 5
+    assert results[0]["iteration"] == 1
 
 
-def test_simulation_endpoint_no_params():
-    resp = client.post("/api/simulations/run", json=[])
+def test_simulation_endpoint_no_params(client: TestClient):
+    scenario_payload = {
+        "name": f"NoParamScenario-{uuid4()}",
+        "description": "No parameters run",
+    }
+    scenario_resp = client.post("/api/scenarios/", json=scenario_payload)
+    assert scenario_resp.status_code == 200
+    scenario_id = scenario_resp.json()["id"]
+
+    resp = client.post(
+        "/api/simulations/run",
+        json={"scenario_id": scenario_id, "parameters": [], "iterations": 10},
+    )
     assert resp.status_code == 400
     assert resp.json()["detail"] == "No parameters provided"
 
 
-def test_simulation_endpoint_success():
-    params = [{"name": "param1", "value": 2.5}]
-    resp = client.post("/api/simulations/run", json=params)
+def test_simulation_endpoint_success(
+    client: TestClient, db_session: Session
+):
+    scenario_payload = {
+        "name": f"SimScenario-{uuid4()}",
+        "description": "Simulation test",
+    }
+    scenario_resp = client.post("/api/scenarios/", json=scenario_payload)
+    assert scenario_resp.status_code == 200
+    scenario_id = scenario_resp.json()["id"]
+
+    params = [
+        {"name": "param1", "value": 2.5, "distribution": "normal", "std_dev": 0.5}
+    ]
+    payload = {
+        "scenario_id": scenario_id,
+        "parameters": params,
+        "iterations": 10,
+        "seed": 42,
+    }
+
+    resp = client.post("/api/simulations/run", json=payload)
     assert resp.status_code == 200
     data = resp.json()
-    assert isinstance(data, list)
+    assert data["scenario_id"] == scenario_id
+    assert len(data["results"]) == 10
+    assert data["summary"]["count"] == 10
+
+    db_session.expire_all()
+    persisted = (
+        db_session.query(SimulationResult)
+        .filter(SimulationResult.scenario_id == scenario_id)
+        .all()
+    )
+    assert len(persisted) == 10
+
+
+def test_simulation_endpoint_uses_stored_parameters(client: TestClient):
+    scenario_payload = {
+        "name": f"StoredParams-{uuid4()}",
+        "description": "Stored parameter simulation",
+    }
+    scenario_resp = client.post("/api/scenarios/", json=scenario_payload)
+    assert scenario_resp.status_code == 200
+    scenario_id = scenario_resp.json()["id"]
+
+    parameter_payload = {
+        "scenario_id": scenario_id,
+        "name": "grade",
+        "value": 1.5,
+    }
+    param_resp = client.post("/api/parameters/", json=parameter_payload)
+    assert param_resp.status_code == 200
+
+    resp = client.post(
+        "/api/simulations/run",
+        json={"scenario_id": scenario_id, "iterations": 3, "seed": 7},
+    )
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["summary"]["count"] == 3
+    assert len(data["results"]) == 3