Refactor admin procedures into separate files

Extract admin procedures from router.ts into dedicated files under
procedures/admin/ with consolidated exports via _routes.ts. Adds shared
helper functions for response transformation and includes race condition
fixes via transaction-scoped existence checks.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api-server/src/procedures/admin/helpers.ts

@@ -0,0 +1,35 @@
+/**
+ * Admin procedure helpers - shared transformation functions
+ */
+
+import type { Selectable } from "kysely";
+import type { Orgs, OrgSites, Users } from "@reviq/db-schema";
+
+/** Transform org record to API response format */
+export const toOrgResponse = (org: Selectable<Orgs>) => ({
+  id: org.id,
+  slug: org.slug,
+  displayName: org.display_name,
+  logoUrl: org.logo_url,
+  createdAt: org.created_at,
+});
+
+/** Transform user record to API response format */
+export const toUserResponse = (user: Selectable<Users>) => ({
+  id: user.id,
+  email: user.email,
+  displayName: user.display_name,
+  fullName: user.full_name,
+  phoneNumber: user.phone_number,
+  avatarUrl: user.avatar_url,
+  emailVerified: user.email_verified_at !== null,
+  needsSetup: user.display_name === null,
+  isSuperuser: user.is_superuser,
+});
+
+/** Transform site record to API response format */
+export const toSiteResponse = (site: Selectable<OrgSites>) => ({
+  id: site.id,
+  domain: site.domain,
+  createdAt: site.created_at,
+});