feat: delete habits from detail sheet

backend/mvp.py

@@ -630,6 +630,14 @@ async def archive_habit(habit_id: UUID, user: User = Depends(current_user), db:
     row = await owned_habit(db, user.id, habit_id); row.archived_at = utcnow(); await db.commit(); return Response(status_code=204)
 
 
+@router.delete("/habits/{habit_id}/permanent", status_code=204)
+async def delete_habit_permanently(habit_id: UUID, user: User = Depends(current_user), db: AsyncSession = Depends(get_db)):
+    row = await owned_habit(db, user.id, habit_id)
+    await db.delete(row)
+    await db.commit()
+    return Response(status_code=204)
+
+
 @router.post("/habits/{habit_id}/logs")
 async def add_habit_log(habit_id: UUID, payload: HabitLogInput, user: User = Depends(current_user), db: AsyncSession = Depends(get_db)):
     habit = await owned_habit(db, user.id, habit_id)