OpenReception: GET appointment by ID returns full appointment record without authorization

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.1.0, the GET handler at `/api/tenants/{id}/appointments/{appointmentId}` performs no authorization check before returning the appointment record. Any party who knows or obtains a valid appointment UUID receives the full row, including channel and agent IDs, time and timezone, status, and the AES-GCM ciphertext components (`encryptedPayload`, `iv`, `authTag`, `dataKey`). The same file's DELETE handler calls `checkPermission(locals, tenantId, true)` before allowing deletion. The intent is clear: appointment records are tenant-scoped and require authentication to access. The GET handler is missing the equivalent call. The middleware chain (`apiAuthHandle`, `authGuard`) does not compensate: API paths bypass `authGuard` entirely, and `apiAuthHandle` does not block requests to non-admin paths when no token is present. Version 1.1.0 patches the issue.