API: Phoenix railing proxy, API key auth for /api/v1/*, schema export, docs, migrations, tests

- Phoenix API Railing: proxy to PHOENIX_RAILING_URL, tenant me routes
- Tenant-auth: X-API-Key support for /api/v1/* (api_keys table)
- Migration 026: api_keys table; 025 sovereign stack marketplace
- GET /graphql/schema, GET /graphql-playground, api/docs OpenAPI
- Integration tests: phoenix-railing.test.ts
- docs/api/API_VERSIONING: /api/v1/ railing alignment
- docs/phoenix/PORTAL_RAILING_WIRING

Made-with: Cursor

api/.env.template

@@ -0,0 +1,11 @@
+# Database Configuration
+# IMPORTANT: Update DB_PASSWORD with your actual PostgreSQL password
+DB_HOST=localhost
+DB_PORT=5432
+DB_NAME=sankofa
+DB_USER=postgres
+DB_PASSWORD=YOUR_ACTUAL_DATABASE_PASSWORD_HERE
+
+# Application Configuration
+NODE_ENV=development
+PORT=4000