Add internal org chat (phase 1) with DM, groups, and org settings.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/src/conversations/conversations-permissions.ts

@@ -0,0 +1,21 @@
+import type { RolePermissionKey, UserRole } from '@mento/shared';
+import { sanitizePermissions } from '../org-roles/role-defaults';
+
+export type ConversationAccess = {
+  canUse: boolean;
+  canCreateGroup: boolean;
+};
+
+export function resolveConversationAccess(
+  membershipRole: UserRole | string,
+  orgRolePermissions: unknown,
+): ConversationAccess {
+  if (membershipRole === 'owner' || membershipRole === 'admin') {
+    return { canUse: true, canCreateGroup: true };
+  }
+  const permissions = sanitizePermissions(orgRolePermissions) as RolePermissionKey[];
+  return {
+    canUse: permissions.includes('conversations'),
+    canCreateGroup: permissions.includes('conversations_groups'),
+  };
+}