Phase 2: 轉換管線 — 五個本地轉換器 + convert.py 統一入口 + selfcheck

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tools/convert/from_web.py

@@ -0,0 +1,53 @@
+"""網頁 URL → 完整 HTML 快照 + Markdown 正文萃取（trafilatura，全程本地處理）。
+
+可獨立執行：python tools/convert/from_web.py <url> [-o out.md] [--snapshot out.html] [--dry-run]
+"""
+import argparse
+import pathlib
+
+import trafilatura
+
+
+def fetch(url):
+    """抓取 URL，回傳完整 HTML 字串。失敗時拋 RuntimeError。"""
+    html = trafilatura.fetch_url(url)
+    if not html:
+        raise RuntimeError(f"抓取失敗：{url}")
+    return html
+
+
+def extract(html):
+    """HTML → Markdown 正文。回傳 (markdown, status)。萃取不到正文時 status='empty'。"""
+    md = trafilatura.extract(
+        html, output_format="markdown", include_tables=True, include_links=True
+    )
+    if not md or not md.strip():
+        return "", "empty"
+    return md.strip(), "ok"
+
+
+def main(argv=None):
+    ap = argparse.ArgumentParser(description=__doc__)
+    ap.add_argument("url")
+    ap.add_argument("-o", "--output")
+    ap.add_argument("--snapshot", help="HTML 快照輸出路徑")
+    ap.add_argument("--dry-run", action="store_true")
+    a = ap.parse_args(argv)
+    html = fetch(a.url)
+    md, status = extract(html)
+    if a.dry_run:
+        print(f"[dry-run] {a.url}: status={status}, snapshot {len(html)} chars, "
+              f"markdown {len(md)} chars")
+        return
+    if status != "ok":
+        print(f"empty: {a.url} 萃取不到正文")
+        raise SystemExit(2)
+    if a.snapshot:
+        pathlib.Path(a.snapshot).write_text(html, encoding="utf-8")
+    out = pathlib.Path(a.output) if a.output else pathlib.Path("page.md")
+    out.write_text(md, encoding="utf-8")
+    print(out)
+
+
+if __name__ == "__main__":
+    main()