Add user-selectable year to standalone household creation

Summary

Add year selection UI to the standalone household creation flow (/[country]/households/create) to match the report pathway's year selection capability.

Background

PR #489 fixed the "Configuration Error" in standalone household creation by wrapping PopulationPathwayWrapper with ReportYearProvider using CURRENT_YEAR as the default. This unblocks users from creating households directly.

However, the standalone flow currently hardcodes CURRENT_YEAR = '2025', while the report pathway allows users to select their desired year in ReportLabelView.

Current Behavior

• Report pathway: User selects year → reportState.year → passed to ReportYearProvider
• Standalone pathway: Year hardcoded to CURRENT_YEAR ('2025')

Proposed Enhancement

Add a year selector step or dropdown to the standalone household flow, similar to how the report pathway handles it in ReportLabelView.

Implementation Options

1. Add year field to household builder form - Inline with other household inputs

Related

• PR #489 - Fixed Configuration Error by adding ReportYearProvider
• Issue #463 - Original bug report
• ReportPathwayWrapper.tsx:602-604 - How report pathway handles year context
• ReportLabelView - Where report pathway collects year from user

Files to Modify

• app/src/pathways/population/PopulationPathwayWrapper.tsx
• Potentially add new view component for year selection