SQLite schema (v9a) has meas_id in photos table, but PostgreSQL
schema (v9b) was missing it. This caused migration to fail.
Added meas_id as nullable UUID column for backward compatibility.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
PostgreSQL does not support IF NOT EXISTS for CREATE TRIGGER.
Use DROP TRIGGER IF EXISTS before CREATE TRIGGER instead.
Fixes: Backend crash loop due to schema.sql syntax error on line 231
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
