feat: SolaceNet gateway rails, IRU marketplace hardening, and docs

- Gateway adapter registry, rails routes, optional SOLACENET_GATEWAY_RAILS_ENFORCE; HTTP integration tests.
- IRU marketplace: rate limits, public routes, notifications/SMTP env docs; marketplace UI constants and flows.
- Quantum proxy legacy protocol types; debank/tezos/GSDS touch-ups; .env.example operator notes.
- SolaceNet doc set (gaps, runbooks, telecom schema example).

Tests: npm run test:iru-marketplace, npm run test:gateway (pass).
Note: full-repo tsc still reports unrelated legacy errors outside this change set.
Made-with: Cursor

marketplace/gateway-microservices-offering.json

@@ -3,7 +3,9 @@
   "name": "DBIS Gateway Microservices",
   "version": "1.0.0",
   "category": "integration",
-  "description": "Regulated-grade integration fabric for financial rails",
+  "protocolMaintainer": "SolaceNet",
+  "governanceDoc": "docs/solacenet/RAIL_AND_PROTOCOL_GOVERNANCE.md",
+  "description": "SolaceNet-maintained gateway rail adapters and HTTP surface for financial messaging rails. Adapter contracts and governance are under SolaceNet (see governanceDoc). Most listed rails are integration scaffolds until production connectors (SWIFTNet, DTCC APIs, etc.) are live — see dbis_core/docs/solacenet/PROTOCOL_GAPS_CHECKLIST.md. KTT Legacy is evidence-oriented (validate/receive); symmetric send is not a production bank rail in the current adapter.",
   "capabilities": [
     "gateway-microservices",
     "gateway-edge",