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.

services/repositories.py

@@ -15,7 +15,6 @@ from models import (
     PricingImpuritySettings,
     PricingMetalSettings,
     PricingSettings,
-    ResourceType,
     Role,
     Scenario,
     ScenarioStatus,
@@ -88,8 +87,12 @@ class ProjectRepository:
         try:
             self.session.flush()
         except IntegrityError as exc:  # pragma: no cover - reliance on DB constraints
+            from monitoring.metrics import observe_project_operation
+            observe_project_operation("create", "error")
             raise EntityConflictError(
                 "Project violates uniqueness constraints") from exc
+        from monitoring.metrics import observe_project_operation
+        observe_project_operation("create", "success")
         return project
 
     def find_by_names(self, names: Iterable[str]) -> Mapping[str, Project]:
@@ -251,7 +254,11 @@ class ScenarioRepository:
         try:
             self.session.flush()
         except IntegrityError as exc:  # pragma: no cover
+            from monitoring.metrics import observe_scenario_operation
+            observe_scenario_operation("create", "error")
             raise EntityConflictError("Scenario violates constraints") from exc
+        from monitoring.metrics import observe_scenario_operation
+        observe_scenario_operation("create", "success")
         return scenario
 
     def find_by_project_and_names(