feat(memory): add memory extension with core functionality and tests

- Implemented MemoryStore class for managing concepts with YAML frontmatter.
- Added methods for creating, reading, updating, and deleting concepts.
- Introduced locking mechanism for concurrent access.
- Developed search and hinting capabilities for concept retrieval.
- Created tests for access control and store functionality.
- Added long-term memory skill documentation and operational guidelines.
- Included package.json and package-lock.json for dependency management.

extensions/memory/test/access.test.mjs

@@ -0,0 +1,31 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { MemoryTurnAccess } from "../access.mjs";
+
+test("requires current-turn search and read before updating an existing concept", () => {
+  const access = new MemoryTurnAccess();
+  assert.throws(() => access.requireWrite("projects/atlas", true), /memory_search/);
+
+  access.recordSearch(["projects/atlas"]);
+  assert.throws(() => access.requireWrite("projects/atlas", true), /read existing concept/);
+
+  access.recordRead(["projects/atlas"]);
+  assert.doesNotThrow(() => access.requireWrite("projects/atlas", true));
+});
+
+test("new concepts require duplicate search but cannot be read unless returned", () => {
+  const access = new MemoryTurnAccess();
+  access.recordSearch([]);
+  assert.doesNotThrow(() => access.requireWrite("projects/new-project", false));
+  assert.throws(() => access.requireSearchedId("projects/new-project"), /exact concept/);
+});
+
+test("turn reset removes prior authorization", () => {
+  const access = new MemoryTurnAccess();
+  access.recordSearch(["people/alice"]);
+  access.recordRead(["people/alice"]);
+  assert.doesNotThrow(() => access.requireForget("people/alice"));
+
+  access.reset();
+  assert.throws(() => access.requireForget("people/alice"), /this user turn/);
+});