Add database optimizations for photo search and pagination

Implement database-level sorting with composite indexes for efficient date and tag queries. Add pagination metadata support and optimize tag count queries using batch processing.

migrations/2026-01-18-000000_optimize_photo_search/down.sql

@@ -0,0 +1,4 @@
+-- Revert search performance optimization indexes
+
+DROP INDEX IF EXISTS idx_image_exif_date_path;
+DROP INDEX IF EXISTS idx_tagged_photo_count;