Treat KiCad Value/PNM as the IC MPN when the MPN column is empty.

Those 13 U* were in the BOM (TPS22965, TPD2E007, TMP117, …) but never entered ic_mpns, so review skipped them as missing PDFs. Also try the BOM Datasheet URL first.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/pinscopex/graph.py

@@ -301,7 +301,9 @@ def build_graph(
     for ref, footprint in parts.items():
         bom_entry = bom.get(ref, {})
         value = bom_entry.get("value", "")
-        mpn = bom_entry.get("mpn")
+        mpn = bom_entry.get("mpn") or None
+        if not mpn and _classify_component(ref, footprint) == ComponentType.IC:
+            mpn = (value or "").strip() or None
 
         components[ref] = Component(
             reference=ref,