feat(p9): real-egress proof (env-gated HttpProvider) + /health bindings + smoke

Task 9.5: /health now reports the egress provider backing each channel (sandbox
vs http). scripts/smoke-capability.mjs proves the slice end to end: sandbox egress
SENT through the broker; EMAIL routed to the env-gated HttpProvider and actually
delivered to a LOCAL echo server (real egress, no external network, no credentials);
idempotent replay; /health bindings. App wires CapabilityModule.

P9 slice-1 verification: 103 tests green, pnpm -r build all packages+demos,
boundary clean, capability smoke PASS, all prior smokes (realtime/inbox/support/
adapter/route/ai/calendar) still PASS through the broker.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/iios-service/src/health.controller.ts

@@ -1,12 +1,16 @@
 import { Controller, Get } from '@nestjs/common';
 import { PrismaService } from './prisma/prisma.service';
+import { CapabilityProviderRegistry } from './capability/capability.registry';
 
 @Controller('health')
 export class HealthController {
-  constructor(private readonly prisma: PrismaService) {}
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly providers: CapabilityProviderRegistry,
+  ) {}
 
   @Get()
-  async check(): Promise<{ status: string; db: boolean }> {
+  async check(): Promise<{ status: string; db: boolean; egressProviders: Record<string, string> }> {
     let db = false;
     try {
       await this.prisma.$queryRaw`SELECT 1`;
@@ -14,6 +18,7 @@ export class HealthController {
     } catch {
       db = false;
     }
-    return { status: 'ok', db };
+    // Ops view: which provider (sandbox vs http) backs each egress channel.
+    return { status: 'ok', db, egressProviders: this.providers.bindings() };
   }
 }