feat(templates): T4 sendTemplated() + outbound provenance

- IiosOutboundCommand gains templateKey/version/locale/renderedHash (migration).
- OutboundService.send accepts an optional opaque `provenance` and writes it into
  the command on BOTH the PENDING and RATE_LIMITED create paths — the only way to
  stamp provenance by construction, since send() creates the row itself (review
  finding). OutboundService still neither renders nor resolves templates.
- TemplatedSender.sendTemplated: render -> OutboundService.send -> provenance, one
  entry point. EMAIL payload = {subject,html,text}; SMS = {text}. Idempotent per key.

Tests: 4 sender + 16 adapters regression green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

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

@@ -34,8 +34,18 @@ export class OutboundService {
     idempotencyKey?: string,
     scopeId?: string,
     purpose?: string,
+    /** Opaque template provenance recorded on the command. OutboundService neither renders nor
+     *  resolves templates — it only persists the four strings it is handed (guaranteed by the
+     *  templated sender, never by caller convention). */
+    provenance?: { templateKey?: string | null; templateVersion?: number | null; templateLocale?: string | null; renderedHash?: string | null },
   ) {
     const key = idempotencyKey ?? randomUUID();
+    const prov = {
+      templateKey: provenance?.templateKey ?? null,
+      templateVersion: provenance?.templateVersion ?? null,
+      templateLocale: provenance?.templateLocale ?? null,
+      renderedHash: provenance?.renderedHash ?? null,
+    };
 
     // The actual send. The inner findUnique stays as a backstop so a FAILED-then-retried
     // command returns the existing row instead of colliding on idempotencyKey @unique.
@@ -46,14 +56,14 @@ export class OutboundService {
       // Per-target rate limit AND per-tenant quota (a noisy tenant can't starve shared egress).
       if (!(await this.allow(channelType, target)) || !(await this.allowTenant(scopeId))) {
         const cmd = await this.prisma.iiosOutboundCommand.create({
-          data: { channelType, target, scopeId, payload: payload as Prisma.InputJsonValue, status: 'RATE_LIMITED', idempotencyKey: key },
+          data: { channelType, target, scopeId, payload: payload as Prisma.InputJsonValue, status: 'RATE_LIMITED', idempotencyKey: key, ...prov },
         });
         await this.prisma.iiosDeliveryAttempt.create({ data: { commandId: cmd.id, attemptNo: 1, status: 'RATE_LIMITED' } });
         return cmd;
       }
 
       const cmd = await this.prisma.iiosOutboundCommand.create({
-        data: { channelType, target, scopeId, payload: payload as Prisma.InputJsonValue, status: 'PENDING', idempotencyKey: key },
+        data: { channelType, target, scopeId, payload: payload as Prisma.InputJsonValue, status: 'PENDING', idempotencyKey: key, ...prov },
       });
 
       let result;