fix: make init-prod create database if it doesn't exist

Add migration step (Step 0/5) to init-prod to ensure the database
exists before running initialization scripts. This allows init-prod
to be run standalone without requiring migrate-up first.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Makefile

@@ -97,6 +97,9 @@ migrate-status:
 init-prod:
 	@echo "🔧 Initializing production database..."
 	@echo ""
+	@echo "Step 0/5: Ensuring database exists (running migrations)..."
+	@$(PYTHON) -m alembic upgrade head
+	@echo ""
 	@echo "Step 1/5: Creating admin user and platform settings..."
 	$(PYTHON) scripts/init_production.py
 	@echo ""