feat(adminsite): create and renew a free instance

Adds the create form with a live slug preview, a renew action inside the
seven-day window, and a deletion countdown that renders only when the
backend has actually promised a date.

The progress bar denominator now follows the tier; a 30-day Free licence
was rendering as an 8% sliver against the hardcoded 365.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

adminsite/lib/api.ts

@@ -57,7 +57,7 @@ const post = <T,>(path: string, payload?: unknown) =>
 
 export type Deployment = "cloud" | "self_hosted";
 export type Tier = "free" | "professional" | "self_hosted";
-export type InstanceStatus = "awaiting_link" | "active" | "lapsed" | "cancelled";
+export type InstanceStatus = "awaiting_link" | "active" | "lapsed" | "cancelled" | "deleted";
 
 export interface Session {
     kind: "staff" | "customer";
@@ -91,6 +91,7 @@ export interface Instance {
     current_license?: string;
     relink_count: number;
     inject_failed_at?: string | null;
+    notices_sent?: string[];
     created_at: string;
 }
 
@@ -187,6 +188,8 @@ export const api = {
     account: () => req<AccountResponse>("/api/account"),
     link: (instance_id: string, name: string) =>
         post<Instance>("/api/instances/link", { instance_id, name }),
+    createInstance: (name: string) => post<Instance>("/api/instances", { name }),
+    renewInstance: (id: string) => post<License>(`/api/instances/${id}/renew`, {}),
     relink: (id: string, instance_id: string) =>
         post<License>(`/api/instances/${id}/relink`, { instance_id }),
     license: (id: string) => req<License & { blob?: string }>(`/api/instances/${id}/license`),