refactor: replace Next.js server with Uvicorn for backend, remove backfill script

app/epub_parser.py

@@ -0,0 +1,38 @@
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any
+
+import html2text
+from ebooklib import ITEM_DOCUMENT
+from ebooklib import epub as epublib
+
+
+def _html_to_text(html_content: str) -> str:
+    h = html2text.HTML2Text()
+    h.ignore_links = True
+    h.ignore_images = True
+    h.ignore_emphasis = False
+    h.body_width = 0
+    return h.handle(html_content).strip()
+
+
+def build_chapters_from_epub(epub_path: Path) -> list[dict[str, Any]]:
+    book = epublib.read_epub(str(epub_path), options={"ignore_ncx": False})
+    out: list[dict[str, Any]] = []
+    idx = 1
+    for item in book.get_items_of_type(ITEM_DOCUMENT):
+        content = item.get_content().decode("utf-8", errors="replace")
+        txt = _html_to_text(content)
+        if not txt:
+            continue
+        out.append(
+            {
+                "number": idx,
+                "title": item.get_name() or f"Chapter {idx}",
+                "content": content,
+                "txt": txt,
+            }
+        )
+        idx += 1
+    return out