feat(ui): add mark-delivered button on sent postcards with auto today date

app/routers/web.py

@@ -339,6 +339,27 @@ def postcard_delete(postcard_id: int, user: User = Depends(get_current_user_web)
     return _redirect(f"/profiles/{pid}/postcards")
 
 
+@router.post("/postcards/{postcard_id}/mark-delivered")
+def mark_delivered(
+    postcard_id: int,
+    user: User = Depends(get_current_user_web),
+    db: Session = Depends(get_db),
+):
+    pc = (
+        db.query(Postcard)
+        .join(Profile)
+        .filter(Postcard.id == postcard_id, Profile.user_id == user.id)
+        .first()
+    )
+    if not pc:
+        return _redirect("/profiles")
+    pc.status = "delivered"
+    if not pc.arrival_time:
+        pc.arrival_time = datetime.now()
+    db.commit()
+    return _redirect(f"/postcards/{postcard_id}")
+
+
 # ---------- Image Upload ----------
 
 @router.post("/postcards/{postcard_id}/image/{side}")