Ship Sprint 0 CAD foundations so findings, KiCad hierarchy, BOM match, eval, and optional PCB ingest have a stable contract.

Extend Finding with rule_id/net/pins, flatten multi-sheet .kicad_sch, flag MPN mismatches, score simple_project, and parse .kicad_pcb without running layout DRC.

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

tests/test_finding_schema.py

@@ -0,0 +1,84 @@
+"""Finding schema — optional CAD/plugin fields, backward compatible.
+
+Favor: legacy JSON still validates; new fields round-trip; pin-mux
+fills rule_id + net + pins.
+Against: invalid status rejected; pins must be a list; extra junk status
+does not silently coerce.
+"""
+
+from __future__ import annotations
+
+import json
+
+import pytest
+from pydantic import ValidationError
+
+from backend.pinscopex.models import Finding
+
+
+def test_legacy_json_without_new_fields_still_validates():
+    raw = {
+        "designator": "U3",
+        "mpn": "MSPM0G3507SPTR",
+        "finding": "Missing decoupling",
+        "why": "Datasheet requires 100n close to VDD",
+        "status": "ERROR",
+        "reference": "p.12",
+    }
+    f = Finding.model_validate(raw)
+    assert f.net is None
+    assert f.pins == []
+    assert f.rule_id is None
+    assert f.cad_sheet is None
+    assert f.cad_uuid is None
+    assert f.variant is None
+
+
+def test_new_fields_round_trip_json():
+    f = Finding(
+        designator="U1",
+        mpn="SPX3819",
+        finding="Cin too far",
+        status="WARNING",
+        net="VIN",
+        pins=["U1.1", "C1.1"],
+        rule_id="PS-DEC-001",
+        cad_sheet="power.kicad_sch",
+        cad_uuid="aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa",
+        variant="DNP",
+    )
+    dumped = json.loads(f.model_dump_json())
+    again = Finding.model_validate(dumped)
+    assert again.net == "VIN"
+    assert again.pins == ["U1.1", "C1.1"]
+    assert again.rule_id == "PS-DEC-001"
+    assert again.cad_sheet == "power.kicad_sch"
+    assert again.cad_uuid == "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa"
+    assert again.variant == "DNP"
+
+
+def test_unknown_extra_keys_do_not_break_legacy_payloads():
+    f = Finding.model_validate(
+        {
+            "designator": "R1",
+            "finding": "ok",
+            "status": "INFO",
+            "future_field_from_old_report": True,
+        }
+    )
+    assert f.designator == "R1"
+
+
+def test_invalid_status_is_rejected():
+    with pytest.raises(ValidationError):
+        Finding(designator="U1", finding="x", status="error")
+
+
+def test_pins_must_be_a_list_not_a_string():
+    with pytest.raises(ValidationError):
+        Finding(designator="U1", finding="x", status="INFO", pins="U1.1")
+
+
+def test_status_ok_is_not_silently_accepted():
+    with pytest.raises(ValidationError):
+        Finding(designator="U1", finding="x", status="OK")