feat: Implement initial capex calculation feature

- Added CapexComponentInput, CapexParameters, CapexCalculationRequest, CapexCalculationResult, and related schemas for capex calculations.
- Introduced calculate_initial_capex function to aggregate capex components and compute totals and timelines.
- Created ProjectCapexRepository and ScenarioCapexRepository for managing capex snapshots in the database.
- Developed capex.html template for capturing and displaying initial capex data.
- Registered common Jinja2 filters for formatting currency and percentages.
- Implemented unit and integration tests for capex calculation functionality.
- Updated unit of work to include new repositories for capex management.

routes/reports.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from datetime import date, datetime
+from datetime import date
 
 from fastapi import APIRouter, Depends, HTTPException, Query, Request, status
 from fastapi.encoders import jsonable_encoder
@@ -24,96 +24,11 @@ from services.reporting import (
     validate_percentiles,
 )
 from services.unit_of_work import UnitOfWork
+from routes.template_filters import register_common_filters
 
 router = APIRouter(prefix="/reports", tags=["Reports"])
 templates = Jinja2Templates(directory="templates")
-
-# Add custom Jinja2 filters
-
-
-def format_datetime(value):
-    """Format a datetime object for display in templates."""
-    if not isinstance(value, datetime):
-        return ""
-    if value.tzinfo is None:
-        # Assume UTC if no timezone
-        from datetime import timezone
-        value = value.replace(tzinfo=timezone.utc)
-    # Format as readable date/time
-    return value.strftime("%Y-%m-%d %H:%M UTC")
-
-
-def currency_display(value, currency_code):
-    """Format a numeric value with currency symbol/code."""
-    if value is None:
-        return "—"
-
-    # Format the number
-    if isinstance(value, (int, float)):
-        formatted_value = f"{value:,.2f}"
-    else:
-        formatted_value = str(value)
-
-    # Add currency code
-    if currency_code:
-        return f"{currency_code} {formatted_value}"
-    return formatted_value
-
-
-def format_metric(value, metric_name, currency_code=None):
-    """Format metric values appropriately based on metric type."""
-    if value is None:
-        return "—"
-
-    # For currency-related metrics, use currency formatting
-    currency_metrics = {'npv', 'inflows', 'outflows',
-                        'net', 'total_inflows', 'total_outflows', 'total_net'}
-    if metric_name in currency_metrics and currency_code:
-        return currency_display(value, currency_code)
-
-    # For percentage metrics
-    percentage_metrics = {'irr', 'payback_period'}
-    if metric_name in percentage_metrics:
-        if isinstance(value, (int, float)):
-            return f"{value:.2f}%"
-        return f"{value}%"
-
-    # Default numeric formatting
-    if isinstance(value, (int, float)):
-        return f"{value:,.2f}"
-
-    return str(value)
-
-
-def percentage_display(value):
-    """Format a value as a percentage."""
-    if value is None:
-        return "—"
-
-    if isinstance(value, (int, float)):
-        return f"{value:.2f}%"
-
-    return f"{value}%"
-
-
-def period_display(value):
-    """Format a period value (like payback period)."""
-    if value is None:
-        return "—"
-
-    if isinstance(value, (int, float)):
-        if value == int(value):
-            return f"{int(value)} years"
-        return f"{value:.1f} years"
-
-    return str(value)
-
-
-templates.env.filters['format_datetime'] = format_datetime
-templates.env.filters['currency_display'] = currency_display
-templates.env.filters['format_metric'] = format_metric
-templates.env.filters['percentage_display'] = percentage_display
-templates.env.filters['period_display'] = period_display
+register_common_filters(templates)
 
 READ_ROLES = ("viewer", "analyst", "project_manager", "admin")
 MANAGE_ROLES = ("project_manager", "admin")