Enhance testing framework and UI feedback

- Updated architecture documentation to include details on UI rendering checks and Playwright end-to-end tests.
- Revised testing documentation to specify Playwright for frontend E2E tests and added details on running tests.
- Implemented feedback mechanism in scenario form for successful creation notifications.
- Added feedback div in ScenarioForm.html for user notifications.
- Created new fixtures for Playwright tests to manage server and browser instances.
- Developed comprehensive E2E tests for consumption, costs, equipment, maintenance, production, and scenarios.
- Added smoke tests to verify UI page loading and form submissions.
- Enhanced unit tests for simulation and validation, including new tests for report generation and validation errors.
- Created new test files for router validation to ensure consistent error handling.
- Established a new test suite for UI routes to validate dashboard and reporting functionalities.
- Implemented validation tests to ensure proper handling of JSON payloads.

tests/unit/test_simulation.py

@@ -4,6 +4,8 @@ import pytest
 from fastapi.testclient import TestClient
 from sqlalchemy.orm import Session
 
+from typing import Any, Dict, List
+
 from models.simulation_result import SimulationResult
 from services.simulation import run_simulation
 
@@ -14,7 +16,7 @@ def client(api_client: TestClient) -> TestClient:
 
 
 def test_run_simulation_function_generates_samples():
-    params = [
+    params: List[Dict[str, Any]] = [
         {"name": "grade", "value": 1.8, "distribution": "normal", "std_dev": 0.2},
         {
             "name": "recovery",
@@ -30,8 +32,73 @@ def test_run_simulation_function_generates_samples():
     assert results[0]["iteration"] == 1
 
 
+def test_run_simulation_with_zero_iterations_returns_empty():
+    params: List[Dict[str, Any]] = [
+        {"name": "grade", "value": 1.2, "distribution": "normal"}
+    ]
+    results = run_simulation(params, iterations=0)
+    assert results == []
+
+
+@pytest.mark.parametrize(
+    "parameter_payload,error_message",
+    [
+        ({"name": "missing-value"}, "Parameter at index 0 must include 'value'"),
+        (
+            {
+                "name": "bad-dist",
+                "value": 1.0,
+                "distribution": "unsupported",
+            },
+            "Parameter 'bad-dist' has unsupported distribution 'unsupported'",
+        ),
+        (
+            {
+                "name": "uniform-range",
+                "value": 1.0,
+                "distribution": "uniform",
+                "min": 5,
+                "max": 5,
+            },
+            "Parameter 'uniform-range' requires 'min' < 'max' for uniform distribution",
+        ),
+        (
+            {
+                "name": "triangular-mode",
+                "value": 5.0,
+                "distribution": "triangular",
+                "min": 1,
+                "max": 3,
+                "mode": 5,
+            },
+            "Parameter 'triangular-mode' mode must be within min/max bounds for triangular distribution",
+        ),
+    ],
+)
+def test_run_simulation_parameter_validation_errors(
+    parameter_payload: Dict[str, Any], error_message: str
+) -> None:
+    with pytest.raises(ValueError) as exc:
+        run_simulation([parameter_payload])
+    assert str(exc.value) == error_message
+
+
+def test_run_simulation_normal_std_dev_fallback():
+    params: List[Dict[str, Any]] = [
+        {
+            "name": "std-dev-fallback",
+            "value": 10.0,
+            "distribution": "normal",
+            "std_dev": 0,
+        }
+    ]
+    results = run_simulation(params, iterations=3, seed=99)
+    assert len(results) == 3
+    assert all("result" in entry for entry in results)
+
+
 def test_simulation_endpoint_no_params(client: TestClient):
-    scenario_payload = {
+    scenario_payload: Dict[str, Any] = {
         "name": f"NoParamScenario-{uuid4()}",
         "description": "No parameters run",
     }
@@ -50,7 +117,7 @@ def test_simulation_endpoint_no_params(client: TestClient):
 def test_simulation_endpoint_success(
     client: TestClient, db_session: Session
 ):
-    scenario_payload = {
+    scenario_payload: Dict[str, Any] = {
         "name": f"SimScenario-{uuid4()}",
         "description": "Simulation test",
     }
@@ -58,10 +125,10 @@ def test_simulation_endpoint_success(
     assert scenario_resp.status_code == 200
     scenario_id = scenario_resp.json()["id"]
 
-    params = [
+    params: List[Dict[str, Any]] = [
         {"name": "param1", "value": 2.5, "distribution": "normal", "std_dev": 0.5}
     ]
-    payload = {
+    payload: Dict[str, Any] = {
         "scenario_id": scenario_id,
         "parameters": params,
         "iterations": 10,
@@ -85,7 +152,7 @@ def test_simulation_endpoint_success(
 
 
 def test_simulation_endpoint_uses_stored_parameters(client: TestClient):
-    scenario_payload = {
+    scenario_payload: Dict[str, Any] = {
         "name": f"StoredParams-{uuid4()}",
         "description": "Stored parameter simulation",
     }
@@ -93,7 +160,7 @@ def test_simulation_endpoint_uses_stored_parameters(client: TestClient):
     assert scenario_resp.status_code == 200
     scenario_id = scenario_resp.json()["id"]
 
-    parameter_payload = {
+    parameter_payload: Dict[str, Any] = {
         "scenario_id": scenario_id,
         "name": "grade",
         "value": 1.5,