feat(iios): register EmailAdapter for EMAIL + email-shaped egress provider

AdapterRegistry now backs the EMAIL channel with the email-native EmailAdapter
(RFC threading) instead of the generic WebhookAdapter. Adds EmailProvider — an
email-envelope egress provider ({to,subject,text,html,inReplyTo}) registered for
EMAIL when IIOS_PROVIDER_URL_EMAIL is set (sandbox stays the default). Spec:
signed email → normalized interaction on the email thread; a reply joins the
same thread (one conversation); bad signature → rejected (fail-closed).

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

packages/iios-service/src/adapters/adapter.registry.ts

@@ -1,6 +1,6 @@
 import { Injectable } from '@nestjs/common';
 import type { ScopeVector } from '@insignia/iios-contracts';
-import { WebhookAdapter, type ChannelAdapter } from '@insignia/iios-adapter-sdk';
+import { WebhookAdapter, EmailAdapter, type ChannelAdapter } from '@insignia/iios-adapter-sdk';
 
 export interface AdapterConfig {
   secret: string;
@@ -8,10 +8,9 @@ export interface AdapterConfig {
 }
 
 /**
- * Registers channel adapters + their per-channel config (secret + scope). In P5
- * one reference WebhookAdapter backs several channelTypes (WEBHOOK/EMAIL/WHATSAPP)
- * so the fixtures exercise the same anti-corruption pipeline. Secrets come from
- * ADAPTER_SECRETS (JSON map); scope defaults to the demo scope.
+ * Registers channel adapters + their per-channel config (secret + scope). EMAIL uses
+ * the email-native EmailAdapter (RFC threading); the rest use the reference
+ * WebhookAdapter. Secrets come from ADAPTER_SECRETS (JSON map); scope defaults to demo.
  */
 @Injectable()
 export class AdapterRegistry {
@@ -29,8 +28,9 @@ export class AdapterRegistry {
       appId: process.env.ADAPTER_APP ?? 'portal-demo',
     };
     for (const channelType of ['WEBHOOK', 'EMAIL', 'WHATSAPP', 'PORTAL']) {
+      const adapter: ChannelAdapter = channelType === 'EMAIL' ? new EmailAdapter() : new WebhookAdapter(channelType);
       this.adapters.set(channelType, {
-        adapter: new WebhookAdapter(channelType),
+        adapter,
         config: { secret: secrets[channelType] ?? 'dev-adapter-secret', scope },
       });
     }

packages/iios-service/src/adapters/adapters.spec.ts

@@ -6,7 +6,7 @@ import { resetDb } from '../test-utils/reset-db';
 import { ProjectionCursorService } from '../projection/projection-cursor.service';
 import { makeFakePorts } from '@insignia/iios-testkit';
 import { IIOS_EVENTS, type CloudEvent } from '@insignia/iios-contracts';
-import { signedFixture, emailFixture } from '@insignia/iios-adapter-sdk';
+import { signedFixture, emailFixture, emailInboundFixture, emailReplyFixture } from '@insignia/iios-adapter-sdk';
 import { AdapterRegistry } from './adapter.registry';
 import { InboundService } from './inbound.service';
 import { OutboundService } from './outbound.service';
@@ -81,6 +81,46 @@ describe('Adapter inbound (P5)', () => {
   });
 });
 
+describe('Email adapter — inbound + threading', () => {
+  const receiveEmail = async (payload: object) => {
+    const { body, headers } = signedFixture(payload, SECRET);
+    return inbound().receive('EMAIL', body, headers);
+  };
+  const normalizeAll = async () => {
+    for (const ev of await rawReceivedEvents()) await projector().onRawReceived(ev);
+  };
+
+  it('a signed inbound email → a normalized interaction with the body on the email thread', async () => {
+    const ack = await receiveEmail(emailInboundFixture);
+    expect(ack.status).toBe('RECEIVED');
+    await normalizeAll();
+
+    const raw = await prisma.iiosInboundRawEvent.findUniqueOrThrow({ where: { id: ack.rawEventId } });
+    expect(raw.status).toBe('NORMALIZED');
+    const interaction = await prisma.iiosInteraction.findUniqueOrThrow({ where: { id: raw.interactionId! }, include: { parts: true, thread: true } });
+    expect(interaction.parts[0]?.bodyText).toBe(emailInboundFixture.text);
+    expect(interaction.thread?.externalThreadRef).toBe('email:<m1@example.com>');
+  });
+
+  it('a reply email (In-Reply-To) lands on the SAME email thread as the original', async () => {
+    await receiveEmail(emailInboundFixture);
+    await receiveEmail(emailReplyFixture);
+    await normalizeAll();
+
+    const interactions = await prisma.iiosInteraction.findMany({ orderBy: { occurredAt: 'asc' } });
+    expect(interactions).toHaveLength(2);
+    expect(interactions[0]!.threadId).toBe(interactions[1]!.threadId); // reply joined the thread
+    expect(await prisma.iiosThread.count()).toBe(1); // one email conversation
+  });
+
+  it('bad signature on EMAIL → REJECTED, nothing ingested (fail-closed)', async () => {
+    const { body } = signedFixture(emailInboundFixture, SECRET);
+    await expect(inbound().receive('EMAIL', body, { 'x-iios-signature': 'sha256=bad' })).rejects.toThrow();
+    expect(await prisma.iiosInboundRawEvent.count({ where: { status: 'REJECTED' } })).toBe(1);
+    expect(await prisma.iiosInteraction.count()).toBe(0);
+  });
+});
+
 describe('Adapter outbound (P5)', () => {
   const outbound = (limit?: number): OutboundService => {
     const s = new OutboundService(asService, new CapabilityBroker(makeFakePorts(), new CapabilityProviderRegistry()), new IdempotencyService(asService));

packages/iios-service/src/capability/capability.registry.ts

@@ -2,6 +2,7 @@ import { Injectable, NotFoundException } from '@nestjs/common';
 import type { CapabilityProvider } from '@insignia/iios-contracts';
 import { SandboxProvider } from './sandbox.provider';
 import { HttpProvider } from './http.provider';
+import { EmailProvider } from './email.provider';
 
 const DEFAULT_CHANNELS = ['WEBHOOK', 'EMAIL', 'WHATSAPP', 'PORTAL'];
 
@@ -19,7 +20,9 @@ export class CapabilityProviderRegistry {
     for (const ch of DEFAULT_CHANNELS) this.register(new SandboxProvider([ch]));
     for (const ch of DEFAULT_CHANNELS) {
       const url = process.env[`IIOS_PROVIDER_URL_${ch}`];
-      if (url) this.register(new HttpProvider(ch, url));
+      if (!url) continue;
+      // EMAIL gets an email-shaped envelope provider; other channels use the generic HTTP one.
+      this.register(ch === 'EMAIL' ? new EmailProvider(url) : new HttpProvider(ch, url));
     }
   }
 

packages/iios-service/src/capability/email.provider.ts

@@ -0,0 +1,40 @@
+import type { CapabilityProvider, CapabilityRequest, ProviderResult } from '@insignia/iios-contracts';
+
+interface EmailPayload {
+  subject?: string;
+  text?: string;
+  html?: string;
+  inReplyTo?: string;
+}
+
+/**
+ * Email egress provider: shapes the outbound command into an email envelope
+ * ({to, subject, text, html, inReplyTo}) and POSTs it to a configured send endpoint
+ * (a vendor mail API / SMTP relay behind a URL). Activated only when
+ * IIOS_PROVIDER_URL_EMAIL is set; a transport failure is surfaced as FAILED, never thrown.
+ */
+export class EmailProvider implements CapabilityProvider {
+  readonly name = 'email-http';
+  readonly channelTypes = ['EMAIL'];
+  readonly capabilities = { canSend: true };
+
+  constructor(private readonly url: string) {}
+
+  async send(req: CapabilityRequest): Promise<ProviderResult> {
+    const started = Date.now();
+    const p = (req.payload ?? {}) as EmailPayload;
+    const email = { to: req.target, subject: p.subject ?? '(no subject)', text: p.text, html: p.html, inReplyTo: p.inReplyTo };
+    try {
+      const res = await fetch(this.url, {
+        method: 'POST',
+        headers: { 'content-type': 'application/json', 'idempotency-key': req.idempotencyKey },
+        body: JSON.stringify(email),
+      });
+      const latencyMs = Date.now() - started;
+      if (!res.ok) return { providerRef: `email-${res.status}`, outcome: 'FAILED', errorCode: `HTTP_${res.status}`, latencyMs };
+      return { providerRef: `email-${req.idempotencyKey}`, outcome: 'SENT', latencyMs };
+    } catch (err) {
+      return { providerRef: 'email-error', outcome: 'FAILED', errorCode: (err as Error).message.slice(0, 60), latencyMs: Date.now() - started };
+    }
+  }
+}