chore: Add last_synced_at columns (#72)

Author: ignaciodob

db/migrations/0009_add_last_synced_at_columns.sql

@@ -0,0 +1,21 @@
+-- Add last_synced_at column to all relevant entity tables
+-- This column tracks when each entity was last synchronized with Orb.
+-- It enables timestamp-based protection to prevent old webhooks from overwriting newer data.
+
+alter table orb.invoices
+add column last_synced_at timestamptz;
+
+alter table orb.customers
+add column last_synced_at timestamptz;
+
+alter table orb.subscriptions
+add column last_synced_at timestamptz;
+
+alter table orb.credit_notes
+add column last_synced_at timestamptz;
+
+alter table orb.plans
+add column last_synced_at timestamptz;
+
+alter table orb.billable_metrics
+add column last_synced_at timestamptz;