update

backend/database.py

@@ -482,6 +482,12 @@ async def set_baustein_score(topic: str, baustein: str, score: int) -> int:
     return score
 
 
+async def delete_baustein_progress(topic: str, baustein: str) -> None:
+    """Fortschritt EINES Bausteins zurücksetzen: Zeile löschen (Score/Streak/Flags/offene Frage).
+    Fehlt die Zeile, liefert get_baustein_progress Defaults (0) — also voller Reset."""
+    db = await get_db()
+    await db.execute("DELETE FROM baustein_progress WHERE topic = ? AND baustein = ?", (topic, baustein))
+    await db.commit()
 
 
 async def set_baustein_verstanden(topic: str, baustein: str) -> bool:

backend/routes.py

@@ -14,7 +14,7 @@ from database import (
     list_progress, set_progress, delete_progress,
     create_element, list_elements, get_element, update_element, delete_element,
     list_baustein_progress, get_baustein_progress, set_offene_frage,
-    set_baustein_score, set_baustein_absolviert, delete_baustein_daten, count_relevant_subs, subs_count_roh,
+    set_baustein_score, set_baustein_absolviert, delete_baustein_daten, delete_baustein_progress, count_relevant_subs, subs_count_roh,
     delete_topic_pipeline, delete_quelle, get_guide_content, delete_guide_content,
 )
 from bausteine import generate_bausteine, cancel_bausteine, bausteine_status, active_bausteine, reset_bausteine, lade_quelle, lade_uebersicht, subbausteine_titel, lade_frage_muster
@@ -179,6 +179,13 @@ async def remove_bausteine(topic: str):
     return {"ok": True}
 
 
+@router.delete("/bausteine/fortschritt")
+async def reset_baustein_fortschritt(topic: str, baustein: str):
+    """Lern-Fortschritt EINES Bausteins auf null (Score/Streak/Flags/offene Frage)."""
+    await delete_baustein_progress(topic, baustein)
+    return {"ok": True}
+
+
 def _validate_quelle(typ: str, ort: str) -> None:
     """Quellen-Eingabe prüfen (gleiche Regeln wie beim Erstellen)."""
     if typ in ("projekt", "uni"):