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_quote_verify.py

@@ -8,7 +8,7 @@ from backend.periscopex.quote_verify import (
     quote_in_text,
     verify_finding_citations,
 )
-from backend.periscopex.validate import _parse_review
+from backend.periscopex.review_parse import parse_submit_review as _parse_review
 from backend.services.llm.pdf_ingest import make_text_pdf