update

backend/routes.py

@@ -162,13 +162,7 @@ async def create_blocks(req: BlocksCreateRequest):
     # Persist the source only the FIRST time; ▶/Resume keeps the existing choice.
     if not qp.exists():
         type, location = req.source_type, req.source_location.strip()
-        if type in ("projekt", "uni"):
-            folder = safe_folder(location)
-            if folder is None or not folder.is_dir():
-                raise HTTPException(400, "Folder invalid or not found (path relative to the project root, no ../).")
-        elif type == "link":
-            if not location.lower().startswith(("http://", "https://")):
-                raise HTTPException(400, "Link must start with http:// or https://.")
+        _validate_source(type, location)
         qp.parent.mkdir(parents=True, exist_ok=True)
         atomic_write_json(qp, {"type": type, "location": location, "spec": req.instructions.strip()})
     asyncio.create_task(generate_blocks(topic, req.instructions.strip(), req.provider,
@@ -315,14 +309,17 @@ async def reset_block_progress(topic: str, block: str):
 
 
 def _validate_source(type: str, location: str) -> None:
-    """Check source input (same rules as on creation)."""
+    """Check source input (shared by create + edit)."""
     if type in ("projekt", "uni"):
         folder = safe_folder(location)
         if folder is None or not folder.is_dir():
             raise HTTPException(400, "Folder invalid or not found (path relative to the project root, no ../).")
     elif type == "link":
-        if not location.lower().startswith(("http://", "https://")):
-            raise HTTPException(400, "Link must start with http:// or https://.")
+        urls = [ln.strip() for ln in location.splitlines() if ln.strip()]
+        if not urls:
+            raise HTTPException(400, "Enter at least one link.")
+        if not all(u.lower().startswith(("http://", "https://")) for u in urls):
+            raise HTTPException(400, "Each link must start with http:// or https:// (one per line).")
 
 
 @router.get("/blocks/source", response_model=BlocksSourceResponse)