Split native Periscope (periscope/src) from inherited PinScope (periscope/dependency).

Keep validate.py and the finding engine as-is. AGPL LICENSE stays at the repo root.
Docker overlays dependency then src. Do not delete the inherited tree.

tests/test_passive_from_distributor.py

@@ -1,3 +1,4 @@
+from tests.paths import SIMPLE_PROJECT, TAXONOMY
 from backend.services.passive_from_distributor import specs_from_distributor
 
 
@@ -91,7 +92,7 @@ def test_auto_resolve_skips_llm_when_catalog_parses(monkeypatch):
         raise AssertionError("LLM must not run")
 
     monkeypatch.setattr("backend.services.extraction.call_with_fallback", boom)
-    tax = Path(__file__).resolve().parents[1] / "taxonomy"
+    tax = TAXONOMY
     model = asyncio.run(
         auto_resolve_specs(
             mpn="CL21B225KPFNNNE",
@@ -115,7 +116,7 @@ def test_auto_resolve_use_llm_false_on_ferrite(monkeypatch):
         raise AssertionError("LLM must not run")
 
     monkeypatch.setattr("backend.services.extraction.call_with_fallback", boom)
-    tax = Path(__file__).resolve().parents[1] / "taxonomy"
+    tax = TAXONOMY
     model = asyncio.run(
         auto_resolve_specs(
             mpn="BLM18PG121SN1D",