feat: Enhance project and scenario creation with monitoring metrics

- Added monitoring metrics for project creation success and error handling in `ProjectRepository`.
- Implemented similar monitoring for scenario creation in `ScenarioRepository`.
- Refactored `run_monte_carlo` function in `simulation.py` to include timing and success/error metrics.
- Introduced new CSS styles for headers, alerts, and navigation buttons in `main.css` and `projects.css`.
- Created a new JavaScript file for navigation logic to handle chevron buttons.
- Updated HTML templates to include new navigation buttons and improved styling for buttons.
- Added tests for reporting service and routes to ensure proper functionality and access control.
- Removed unused imports and optimized existing test files for better clarity and performance.

monitoring/metrics.py

@@ -1,8 +1,7 @@
 from __future__ import annotations
 
-from typing import Iterable
 
-from prometheus_client import Counter, Histogram
+from prometheus_client import Counter, Histogram, Gauge
 
 IMPORT_DURATION = Histogram(
     "calminer_import_duration_seconds",
@@ -28,6 +27,54 @@ EXPORT_TOTAL = Counter(
     labelnames=("dataset", "status", "format"),
 )
 
+# General performance metrics
+REQUEST_DURATION = Histogram(
+    "calminer_request_duration_seconds",
+    "Duration of HTTP requests",
+    labelnames=("method", "endpoint", "status"),
+)
+
+REQUEST_TOTAL = Counter(
+    "calminer_request_total",
+    "Count of HTTP requests",
+    labelnames=("method", "endpoint", "status"),
+)
+
+ACTIVE_CONNECTIONS = Gauge(
+    "calminer_active_connections",
+    "Number of active connections",
+)
+
+DB_CONNECTIONS = Gauge(
+    "calminer_db_connections",
+    "Number of database connections",
+)
+
+# Business metrics
+PROJECT_OPERATIONS = Counter(
+    "calminer_project_operations_total",
+    "Count of project operations",
+    labelnames=("operation", "status"),
+)
+
+SCENARIO_OPERATIONS = Counter(
+    "calminer_scenario_operations_total",
+    "Count of scenario operations",
+    labelnames=("operation", "status"),
+)
+
+SIMULATION_RUNS = Counter(
+    "calminer_simulation_runs_total",
+    "Count of Monte Carlo simulation runs",
+    labelnames=("status",),
+)
+
+SIMULATION_DURATION = Histogram(
+    "calminer_simulation_duration_seconds",
+    "Duration of Monte Carlo simulations",
+    labelnames=("status",),
+)
+
 
 def observe_import(action: str, dataset: str, status: str, seconds: float) -> None:
     IMPORT_TOTAL.labels(dataset=dataset, action=action, status=status).inc()
@@ -40,3 +87,22 @@ def observe_export(dataset: str, status: str, export_format: str, seconds: float
                         format=export_format).inc()
     EXPORT_DURATION.labels(dataset=dataset, status=status,
                            format=export_format).observe(seconds)
+
+
+def observe_request(method: str, endpoint: str, status: int, seconds: float) -> None:
+    REQUEST_TOTAL.labels(method=method, endpoint=endpoint, status=status).inc()
+    REQUEST_DURATION.labels(method=method, endpoint=endpoint,
+                            status=status).observe(seconds)
+
+
+def observe_project_operation(operation: str, status: str = "success") -> None:
+    PROJECT_OPERATIONS.labels(operation=operation, status=status).inc()
+
+
+def observe_scenario_operation(operation: str, status: str = "success") -> None:
+    SCENARIO_OPERATIONS.labels(operation=operation, status=status).inc()
+
+
+def observe_simulation(status: str, duration_seconds: float) -> None:
+    SIMULATION_RUNS.labels(status=status).inc()
+    SIMULATION_DURATION.labels(status=status).observe(duration_seconds)