fix: various small fixes and improvements

- Add 'skipped' to authentication result enum in OpenAPI spec
- Fix optional chaining on bimiResult.details check
- Add rbls field to AppConfig interface
- Restrict theme storage to valid 'light'/'dark' values only
- Fix null coalescing for blacklist result data
- Fix survey source to use domain instead of ip

web/src/routes/blacklist/[ip]/+page.svelte

@@ -28,7 +28,7 @@
             });
 
             if (response.response.ok) {
-                result = response.data;
+                result = response.data ?? null;
             } else if (response.error) {
                 error = response.error.message || "Failed to check IP address";
             }

web/src/routes/domain/[domain]/+page.svelte

@@ -130,7 +130,7 @@
                             <div class="d-flex justify-content-end me-lg-5 mt-3">
                                 <TinySurvey
                                     class="bg-primary-subtle rounded-4 p-3 text-center"
-                                    source={"rbl-" + result.ip}
+                                    source={"domain-" + result.domain}
                                 />
                             </div>
                         </div>