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/runtime-features.d.ts

@@ -0,0 +1,19 @@
+export type FeatureOverrides = {
+    global?: Record<string, boolean>;
+    sets?: Record<string, Record<string, boolean>>;
+};
+type NormalizedFeatureOverrides = {
+    global: Record<string, boolean>;
+    sets: Record<string, Record<string, boolean>>;
+};
+export type FeatureOverridesSnapshot = {
+    cachePath: string;
+    overrides: FeatureOverrides;
+};
+export declare function loadFeatureOverrides(): NormalizedFeatureOverrides;
+export declare function getFeatureOverridesSnapshot(): FeatureOverridesSnapshot;
+export declare function applyFeatureOverrides(setName: string, base: Record<string, boolean>): Record<string, boolean>;
+export declare function refreshFeatureOverridesCache(): Promise<FeatureOverridesSnapshot>;
+export declare function clearFeatureOverridesCache(): void;
+export {};
+//# sourceMappingURL=runtime-features.d.ts.map