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-kernel-client/src/rest.ts

@@ -77,15 +77,21 @@ export class RestClient {
     return ((await r.json()) as { users: string[] }).users;
   }
 
-  /** Server-authoritative conversation list (works cross-device, shows unread + members). */
-  async listThreads(): Promise<ThreadSummary[]> {
-    const r = await fetch(this.url('/v1/threads'), { headers: this.headers() });
+  /**
+   * Server-authoritative conversation list (works cross-device, shows unread + members).
+   * `filter.metadata` narrows to threads whose opaque attribute bag matches every key/value.
+   */
+  async listThreads(filter?: { metadata?: Record<string, string> }): Promise<ThreadSummary[]> {
+    const qs = filter?.metadata
+      ? '?' + Object.entries(filter.metadata).map(([k, v]) => `metadata[${encodeURIComponent(k)}]=${encodeURIComponent(v)}`).join('&')
+      : '';
+    const r = await fetch(this.url(`/v1/threads${qs}`), { headers: this.headers() });
     if (!r.ok) throw new Error(`listThreads ${r.status}`);
     return (await r.json()) as ThreadSummary[];
   }
 
-  /** Create a thread with generic app attributes (membership hint, creator role, subject/name). */
-  async createThread(opts: { membership?: string; creatorRole?: string; subject?: string }): Promise<{ threadId: string }> {
+  /** Create a thread with generic app attributes (membership/creator role/subject + an opaque metadata bag). */
+  async createThread(opts: { membership?: string; creatorRole?: string; subject?: string; metadata?: Record<string, unknown> }): Promise<{ threadId: string }> {
     return this.post<{ threadId: string }>('/v1/threads', opts);
   }
 
@@ -109,11 +115,15 @@ export class RestClient {
   }
 
   // ─── support ──────────────────────────────────────────────────
-  async createTicket(body: { subject: string; priority?: string; threadId?: string }): Promise<Ticket> {
+  async createTicket(body: { subject: string; priority?: string; threadId?: string; metadata?: Record<string, unknown> }): Promise<Ticket> {
     return this.post<Ticket>('/v1/support/tickets', body);
   }
-  async escalate(threadId: string, subject?: string): Promise<Ticket> {
-    return this.post<Ticket>('/v1/support/escalate', { threadId, subject });
+  async escalate(threadId: string, subject?: string, metadata?: Record<string, unknown>): Promise<Ticket> {
+    return this.post<Ticket>('/v1/support/escalate', { threadId, subject, metadata });
+  }
+  /** Manually assign a ticket to a specific user (generic assignment override). */
+  async assignTicket(id: string, userId: string): Promise<Ticket> {
+    return this.post<Ticket>(`/v1/support/tickets/${id}/assignee`, { userId });
   }
   async listTickets(scope: 'mine' | 'assigned' = 'mine'): Promise<Ticket[]> {
     const r = await fetch(this.url(`/v1/support/tickets?scope=${scope}`), { headers: this.headers() });