Add Date Filter Support for Volunteer Activity Trend and Volunteers by Location (#179)

[PamalaMadhumithaYadav]

Summary

Implemented Issue #179 by adding date filter support for the Volunteer Activity Trend and Volunteers by Location widgets in volunteer_application_analytics.py. These filters are consumed by the Super Admin dashboard charts.

Changes

• Added build_date_filter_trend() helper — returns the WHERE clause date condition for Volunteer Activity Trend queries
• Added build_date_filter_location() helper — returns the WHERE clause date condition for Volunteers by Location query
• Added get_grouping() helper — determines daily vs monthly grouping based on time range
• Updated get_volunteer_activity_trend() to support 7D, 30D, 1Y, All, and Custom date filters
• Updated get_volunteers_by_location() to support 7D, 30D, 1Y, All, and Custom date filters (date filtering only — country aggregation logic and response format unchanged)
• Renamed trend response key from month to period
• Updated merge logic to use period
• Trend and location filters are independent (time_range vs time_range_location, with separate custom date params)

Date Filter Behavior

Time Range	Filter	Trend Grouping
7D	Past 7 days	Daily
30D	Past 30 days	Daily
1Y	Past 1 year	Monthly
All	Entire dataset	Monthly
Custom	Between start_date and end_date	Daily

Testing

• Tested locally using CSV files from the sql/ folder loaded into SQLite (per local testing guidelines)
• Verified all 5 time ranges for both widgets, including independent filters and custom date ranges
• Verified period key in all trend responses and cumulative total_volunteers counts
• Applies to both Virginia and Ireland databases
• No production credentials hardcoded

Notes for Reviewers

• LOCAL_TESTING flag is set to False for deployment; when True, the script runs against local CSV data for testing without AWS access