Seeded repo with intent and initial content.

src/emergent_security/memory.py

@@ -0,0 +1,33 @@
+"""Security memory (canon B5). Memory informs; negative memory blocks until cleared (C10)."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Any, Mapping
+
+from emergent_security.model import Request, frozen_mapping
+
+
+@dataclass(frozen=True)
+class MemoryEntry:
+    decision_class: str
+    scope: Mapping[str, Any]
+    polarity: str
+    cleared: bool = False
+
+    @classmethod
+    def from_dict(cls, data: Mapping[str, Any]) -> MemoryEntry:
+        return cls(
+            decision_class=str(data["decision_class"]),
+            scope=frozen_mapping(data.get("scope")),
+            polarity=str(data.get("polarity", "positive")),
+            cleared=bool(data.get("cleared", False)),
+        )
+
+    def blocks(self, request: Request) -> bool:
+        return (
+            self.polarity == "negative"
+            and not self.cleared
+            and self.decision_class == request.decision_class
+            and all(request.scope.get(key) == value for key, value in self.scope.items())
+        )