test: add memory quality eval fixtures

Wave 2 of memory quality optimization plan.

- 5 accepted cases: durable facts that should be kept
- 7 rejected cases: noise that should be filtered
- Parser-level regression guard (zero API call)
- All cases pass against current extractors.ts

tests/memory-quality-eval.test.ts

@@ -0,0 +1,93 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { parseWorkspaceMemoryCandidates } from "../src/extractors.ts";
+
+const acceptedCases = [
+  {
+    name: "durable user language preference",
+    line: "- [feedback] User prefers architecture reviews in Traditional Chinese",
+    expectedType: "feedback",
+    expectedText: /Traditional Chinese/,
+  },
+  {
+    name: "stable cache architecture decision",
+    line: "- [decision] Use frozen workspace memory snapshots plus ephemeral hot state for cache stability",
+    expectedType: "decision",
+    expectedText: /frozen workspace memory/,
+  },
+  {
+    name: "stable zero API call constraint",
+    line: "- [project] The plugin piggybacks memory extraction on OpenCode compaction and should not add extra LLM calls",
+    expectedType: "project",
+    expectedText: /extra LLM calls/,
+  },
+  {
+    name: "hard to rediscover reference",
+    line: "- [reference] Workspace memory uses a frozen system[1] snapshot and pending memories remain in hot session state until compaction",
+    expectedType: "reference",
+    expectedText: /system\[1\]/,
+  },
+  {
+    name: "short stable config reference",
+    line: "- [reference] Config parser supports bracketless format",
+    expectedType: "reference",
+    expectedText: /bracketless/,
+  },
+] as const;
+
+const rejectedCases = [
+  {
+    name: "test count snapshot",
+    line: "- [project] 42 tests passed after the latest implementation",
+  },
+  {
+    name: "suite count snapshot",
+    line: "- [project] 3 suites pass and 0 suites fail right now",
+  },
+  {
+    name: "phase progress snapshot",
+    line: "- [project] Wave 2 completed successfully",
+  },
+  {
+    name: "commit hash",
+    line: "- [reference] Commit 4309cb8 contains the promotion accounting fix",
+  },
+  {
+    name: "raw transient error",
+    line: "- [feedback] TypeError: Cannot read properties of undefined",
+  },
+  {
+    name: "path heavy rediscoverable fact",
+    line: "- [project] Important files are /src/plugin.ts /src/workspace-memory.ts /src/session-state.ts",
+  },
+  {
+    name: "temporary pending task",
+    line: "- [decision] currently: run npm test before the next reply",
+  },
+] as const;
+
+for (const item of acceptedCases) {
+  test(`memory quality accepts ${item.name}`, () => {
+    const summary = `
+Memory candidates:
+${item.line}
+`;
+    const entries = parseWorkspaceMemoryCandidates(summary);
+
+    assert.equal(entries.length, 1);
+    assert.equal(entries[0].type, item.expectedType);
+    assert.match(entries[0].text, item.expectedText);
+  });
+}
+
+for (const item of rejectedCases) {
+  test(`memory quality rejects ${item.name}`, () => {
+    const summary = `
+Memory candidates:
+${item.line}
+`;
+    const entries = parseWorkspaceMemoryCandidates(summary);
+
+    assert.equal(entries.length, 0);
+  });
+}