* fix(db): normalize timestamps and fix recently added album sorting
SQLite stores timestamps as TEXT and uses string comparison for ORDER BY.
Timestamps in RFC3339 T-format ('2024-01-01T10:00:00Z') sort incorrectly
against space-format ('2024-01-01 10:00:00+00:00') because 'T' (ASCII 84)
> ' ' (ASCII 32), causing albums with T-format timestamps to appear as
newer than they are in the "Recently Added" list.
This adds a migration to normalize all T-format timestamps across all
tables to the space-format expected by go-sqlite3, wraps the
recently_added sort with datetime() to make it format-agnostic, and
replaces the plain album timestamp indexes with expression indexes to
maintain query performance.
* fix(test): improve recently_added sort test robustness
Use same-date timestamps (2024-01-15T08:00:00Z vs 2024-01-15 20:00:00)
so the T-vs-space character difference at position 10 actually triggers
the sorting bug. Initialize index variables to -1 and assert both test
albums are found before comparing positions.
* chore(db): update migration timestamp to 2026-03-16
Deluan Quintão