feat(iios): generic opaque metadata + manual ticket assign (glue prereqs)

Generic kernel primitives so app backends (e.g. a CRM support glue) can link
their domain to interactions WITHOUT the kernel learning any app vocabulary:

- thread: accept an opaque `metadata` bag on create (merged with membership),
  echo it in listThreads, and filter listThreads by `?metadata[key]=value`
  (equality on the opaque bag — the kernel never interprets the keys).
- support: accept opaque `metadata` on createTicket/escalate (thread bag
  inherited); add SupportService.assignTo — a policy-gated manual assignment
  of a ticket to a target actor (POST /v1/support/tickets/:id/assignee).
- SDK @insignia/iios-kernel-client 0.1.2: createThread(metadata),
  listThreads({metadata}) filter, createTicket(metadata), escalate(metadata),
  assignTicket; ThreadSummary/Ticket expose the opaque bag.

Generic-safety gate holds: no crm/customer/lead in kernel code (opaque values
only). Tests: +2 (metadata create/filter, ticket metadata + assignTo); 31 pass.

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

packages/iios-service/src/support/support.dto.ts

@@ -1,4 +1,4 @@
-import { IsIn, IsOptional, IsString } from 'class-validator';
+import { IsIn, IsObject, IsOptional, IsString } from 'class-validator';
 
 const PRIORITIES = ['P0', 'P1', 'P2', 'P3', 'P4'] as const;
 const STATES = ['NEW', 'OPEN', 'PENDING_CUSTOMER', 'PENDING_INTERNAL', 'RESOLVED', 'CLOSED', 'CANCELLED'] as const;
@@ -7,11 +7,18 @@ export class CreateTicketDto {
   @IsString() subject!: string;
   @IsOptional() @IsIn(PRIORITIES) priority?: (typeof PRIORITIES)[number];
   @IsOptional() @IsString() threadId?: string;
+  /** Opaque, app-supplied attribute bag — stored on the ticket, never interpreted by the kernel. */
+  @IsOptional() @IsObject() metadata?: Record<string, unknown>;
 }
 
 export class EscalateDto {
   @IsString() threadId!: string;
   @IsOptional() @IsString() subject?: string;
+  @IsOptional() @IsObject() metadata?: Record<string, unknown>;
+}
+
+export class AssignTicketDto {
+  @IsString() userId!: string;
 }
 
 export class PatchTicketDto {