feat(baoyu-url-to-markdown): add URL-specific parser layer for X/Twitter and archive.ph

- New parsers/ module with pluggable rule system for site-specific HTML extraction
- X status parser: extract tweet text, media, quotes, author from data-testid elements
- X article parser: extract long-form article content with inline media
- archive.ph parser: restore original URL and prefer #CONTENT container
- Improved slug generation with stop words and content-aware slugs
- Output path uses subdirectory structure (domain/slug/slug.md)
- Fix: preserve anchor elements containing media in legacy converter
- Fix: smarter title deduplication in markdown document builder

skills/baoyu-url-to-markdown/scripts/html-to-markdown.ts

@@ -12,6 +12,7 @@ import {
   scoreMarkdownQuality,
   shouldCompareWithLegacy,
 } from "./legacy-converter.js";
+import { tryUrlRuleParsers } from "./parsers/index.js";
 
 export type { ConversionResult, PageMetadata };
 export { createMarkdownDocument, formatMetadataYaml };
@@ -105,6 +106,11 @@ export async function extractContent(html: string, url: string): Promise<Convers
   const capturedAt = new Date().toISOString();
   const baseMetadata = extractMetadataFromHtml(html, url, capturedAt);
 
+  const specializedResult = tryUrlRuleParsers(html, url, baseMetadata);
+  if (specializedResult) {
+    return specializedResult;
+  }
+
   const defuddleResult = await tryDefuddleConversion(html, url, baseMetadata);
   if (defuddleResult.ok) {
     if (shouldPreferDefuddle(defuddleResult.result)) {