feat: add domain rules management feature

- Introduced a new DomainRulesPage component for managing custom and global equivalent domains.
- Updated AppMainRoutes to include a route for domain rules.
- Added API functions to fetch and save domain rules.
- Enhanced localization with new strings for domain rules in multiple languages.
- Updated styles for the new domain rules interface and ensured responsiveness.
- Added types for domain rules in the TypeScript definitions.

src/handlers/domains.ts

@@ -0,0 +1,80 @@
+import type { Env } from '../types';
+import { StorageService } from '../services/storage';
+import {
+  buildDomainsResponse,
+  customRulesToActiveEquivalentDomains,
+  normalizeCustomEquivalentDomains,
+  normalizeEquivalentDomains,
+  normalizeExcludedGlobalTypes,
+} from '../services/domain-rules';
+import { errorResponse, jsonResponse } from '../utils/response';
+
+function firstPresent(payload: Record<string, unknown>, keys: string[]): unknown {
+  for (const key of keys) {
+    if (Object.prototype.hasOwnProperty.call(payload, key)) return payload[key];
+  }
+  return undefined;
+}
+
+async function readPayload(request: Request): Promise<Record<string, unknown>> {
+  try {
+    const parsed = await request.json();
+    return parsed && typeof parsed === 'object' && !Array.isArray(parsed)
+      ? parsed as Record<string, unknown>
+      : {};
+  } catch {
+    return {};
+  }
+}
+
+export async function handleGetDomains(env: Env, userId: string): Promise<Response> {
+  const storage = new StorageService(env.DB);
+  const settings = await storage.getUserDomainSettings(userId);
+  return jsonResponse(buildDomainsResponse(
+    settings.equivalentDomains,
+    settings.customEquivalentDomains,
+    settings.excludedGlobalEquivalentDomains
+  ));
+}
+
+export async function handleUpdateDomains(request: Request, env: Env, userId: string): Promise<Response> {
+  const storage = new StorageService(env.DB);
+  const payload = await readPayload(request);
+  const current = await storage.getUserDomainSettings(userId);
+  const equivalentDomainsRaw = firstPresent(payload, [
+    'equivalentDomains',
+    'EquivalentDomains',
+  ]);
+  const customEquivalentDomainsRaw = firstPresent(payload, [
+    'customEquivalentDomains',
+    'CustomEquivalentDomains',
+  ]);
+  const excludedGlobalEquivalentDomainsRaw = firstPresent(payload, [
+    'excludedGlobalEquivalentDomains',
+    'ExcludedGlobalEquivalentDomains',
+    // Some older compatible clients send the excluded type list under this key.
+    'globalEquivalentDomains',
+    'GlobalEquivalentDomains',
+  ]);
+  const customEquivalentDomains = customEquivalentDomainsRaw === undefined
+    ? (equivalentDomainsRaw === undefined
+        ? current.customEquivalentDomains
+        : normalizeCustomEquivalentDomains(normalizeEquivalentDomains(equivalentDomainsRaw)))
+    : normalizeCustomEquivalentDomains(customEquivalentDomainsRaw);
+  const equivalentDomains = customRulesToActiveEquivalentDomains(customEquivalentDomains);
+  const excludedGlobalEquivalentDomains = excludedGlobalEquivalentDomainsRaw === undefined
+    ? current.excludedGlobalEquivalentDomains
+    : normalizeExcludedGlobalTypes(excludedGlobalEquivalentDomainsRaw);
+
+  await storage.saveUserDomainSettings(userId, equivalentDomains, customEquivalentDomains, excludedGlobalEquivalentDomains);
+
+  const settings = await storage.getUserDomainSettings(userId);
+  if (!settings) {
+    return errorResponse('Domain settings unavailable', 500);
+  }
+  return jsonResponse(buildDomainsResponse(
+    settings.equivalentDomains,
+    settings.customEquivalentDomains,
+    settings.excludedGlobalEquivalentDomains
+  ));
+}