refactor: Relocate SQL migration scripts to a dedicated directory and remove deprecated test scripts.

scripts/migrations/migrate-packages-version-length.sql

@@ -0,0 +1,10 @@
+-- Migration: increase packages.version length to 255
+-- Run this against your existing database (PostgreSQL)
+
+ALTER TABLE packages
+  ALTER COLUMN version TYPE VARCHAR(255);
+
+-- Optional: verify
+SELECT column_name, data_type, character_maximum_length
+FROM information_schema.columns
+WHERE table_name = 'packages' AND column_name = 'version';