Merge PR #48: feat: add Xiaohongshu source + Reddit public fallback

- Xiaohongshu search via local MCP service (opt-in, zero impact if service not running)
- Reddit public JSON fallback (works with zero API keys)
- Reddit priority: ScrapeCreators -> OpenAI -> public fallback
- Updated env.py: Reddit always available via public fallback

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

vendor/package/dist/lib/twitter-client-user-lookup.d.ts

@@ -0,0 +1,16 @@
+import type { AbstractConstructor, Mixin, TwitterClientBase } from './twitter-client-base.js';
+import type { AboutAccountResult } from './twitter-client-types.js';
+/** Result of username to userId lookup */
+export interface UserLookupResult {
+    success: boolean;
+    userId?: string;
+    username?: string;
+    name?: string;
+    error?: string;
+}
+export interface TwitterClientUserLookupMethods {
+    getUserIdByUsername(username: string): Promise<UserLookupResult>;
+    getUserAboutAccount(username: string): Promise<AboutAccountResult>;
+}
+export declare function withUserLookup<TBase extends AbstractConstructor<TwitterClientBase>>(Base: TBase): Mixin<TBase, TwitterClientUserLookupMethods>;
+//# sourceMappingURL=twitter-client-user-lookup.d.ts.map