feat(db): add rent_payment_destinations column and multi-schema support

- Add migration 0020 for rent_payment_destinations jsonb column
- Add DB_SCHEMA env var support for multi-schema deployments
- Create custom migrate.ts script with proper search_path handling
- Update drizzle.config.ts and client.ts to use DB_SCHEMA
- Add db_schema variable to Terraform with dev=test/prod=public defaults
- Update CD workflow to set DB_SCHEMA based on branch

packages/db/drizzle/0020_natural_mauler.sql

@@ -0,0 +1 @@
+ALTER TABLE "household_billing_settings" ADD COLUMN "rent_payment_destinations" jsonb;

packages/db/drizzle/meta/_journal.json

@@ -141,6 +141,13 @@
       "when": 1773327708167,
       "tag": "0019_faithful_madame_masque",
       "breakpoints": true
+    },
+    {
+      "idx": 20,
+      "version": "7",
+      "when": 1773590603863,
+      "tag": "0020_natural_mauler",
+      "breakpoints": true
     }
   ]
 }