231f983429
- Add subscription_change_pending_tier and subscription_change_pending_date fields to UserProfile - Create migration 019_add_subscription_change_pending - Add apply_pending_subscription_changes(), request_subscription_change(), cancel_pending_subscription_change() utilities - Add POST /api/subscriptions/change and DELETE /api/subscriptions/change endpoints - Update GET /api/subscriptions/my to apply pending changes and return pending change info - Update subscription view to apply pending changes and pass period_start + pending info - Update subscription.html: per-tier action buttons (upgrade/downgrade/cancel), pending-change banner, period start date - Add Celery daily task apply_pending_subscription_changes_all at 00:05 UTC - Add 19 new tests covering all new utility functions and API endpoints Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>