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/src/schema/typeDefs.ts

@@ -1282,6 +1282,11 @@ export const typeDefs = gql`
     FINANCIAL_MESSAGING
     INTERNET_REGISTRY
     AI_LLM_AGENT
+    LEDGER_SERVICES
+    IDENTITY_SERVICES
+    WALLET_SERVICES
+    ORCHESTRATION_SERVICES
+    PLATFORM_SERVICES
   }
 
   enum ProductStatus {