Stop periscope/src importing PinScope validate.py after live C2 smoke.

PCB review and src checks use native parse, constraints lookup, and
review_session. Inherited validate.py and validation_tools.py stay in
dependency/.

tests/test_validation_concurrency.py

@@ -23,7 +23,7 @@ from pypdf import PdfWriter
 from backend.config import settings
 from backend.periscopex.models import Component, ComponentType, DesignGraph, Finding
 from backend.periscopex.utils import safe_mpn
-from backend.periscopex.validate import ReviewResult
+from backend.periscopex.review_parse import ReviewResult
 from backend.services import validation as val
 from backend.services.api_logs import ApiLogger
 from backend.services.storage import LocalStorageBackend