Take js-yaml 5, with guards for the two behaviour changes it brings

CHANGELOG.md

@@ -41,6 +41,8 @@ and this project follows [Semantic Versioning](https://semver.org/spec/v2.0.0.ht
 - Pending approvals now have an explicit mixed-risk ordering test and panel-side sort to keep critical items pinned before older lower-priority reviews.
 - The approvals panel now shows a queue health summary with pending count, critical count, and oldest waiting item before the pending decision list.
 - Brand asset docs now point at the actual public asset path.
+- Policy and config YAML now parses under the YAML 1.2 core schema on js-yaml 5. Merge keys (`<<`) are no longer expanded, so a policy file that relies on one is rejected whole and the last good ruleset stays in force instead of a partially assembled rule taking effect. Unquoted dates load as strings rather than `Date` objects, and a mapping with a complex key is rejected instead of having that key flattened into a lossy string.
+- The dashboard runtime-context panel now degrades to "none" when the agent harness config file cannot be parsed, rather than failing the whole dashboard state build on a file Agentwall does not own.
 
 ## [0.1.0] - 2026-03-23
 

package.json

@@ -27,13 +27,12 @@
   "license": "Apache-2.0",
   "dependencies": {
     "fastify": "5.11.0",
-    "js-yaml": "^4.1.0",
+    "js-yaml": "5.2.3",
     "pino": "^8.19.0",
     "zod": "4.4.3"
   },
   "devDependencies": {
     "@jest/globals": "^30.4.1",
-    "@types/js-yaml": "^4.0.9",
     "@types/node": "^20.11.5",
     "jest": "^30.4.2",
     "ts-jest": "^29.4.12",

src/dashboard/state.ts

@@ -329,11 +329,21 @@ function yamlTopLevelKeys(source: unknown): string[] {
 }
 
 function summarizeYamlSource(absolutePath: string): { keys: string[]; modelDefault: string | null; modelProvider: string | null; skin: string | null } {
+  const unknownSummary = { keys: [] as string[], modelDefault: null, modelProvider: null, skin: null };
   const text = readTextSafely(absolutePath);
   if (!text) {
-    return { keys: [], modelDefault: null, modelProvider: null, skin: null };
+    return unknownSummary;
+  }
+  // This file belongs to the agent harness, not to us, so it is foreign input: it can hold
+  // nothing but comments, be half-written while an editor saves it, or be deliberately
+  // malformed by whoever can write into the agent home. A parse failure degrades one
+  // dashboard panel to "unknown" instead of taking the whole state build down with it.
+  let parsed: unknown;
+  try {
+    parsed = yaml.load(text);
+  } catch {
+    return unknownSummary;
   }
-  const parsed = yaml.load(text);
   return {
     keys: yamlTopLevelKeys(parsed),
     modelDefault: nestedStringValue(parsed, ["model", "default"]),

tests/dashboard-harness-config.test.ts

@@ -0,0 +1,55 @@
+import { afterAll, describe, expect, it } from "@jest/globals";
+import * as fs from "fs";
+import * as os from "os";
+import * as path from "path";
+
+/**
+ * The dashboard reads the agent harness's own config.yaml to describe the runtime context.
+ * That file belongs to the harness, not to Agentwall, so its bytes are foreign input: it can
+ * hold nothing but comments, be caught half-written while an editor saves it, or be
+ * deliberately malformed by anyone who can write into the agent home. A YAML parse failure
+ * there costs one panel its detail and nothing more, because an attacker who can blind the
+ * whole operator view can then act unobserved.
+ */
+const agentHome = fs.mkdtempSync(path.join(os.tmpdir(), "agentwall-harness-home-"));
+process.env["AGENTWALL_AGENT_HOME"] = agentHome;
+
+afterAll(() => {
+  fs.rmSync(agentHome, { recursive: true, force: true });
+});
+
+// Loaded through await import, not a static import, because state.ts resolves
+// AGENTWALL_AGENT_HOME once at module load and static imports are evaluated before the
+// assignment above runs. This test exercises that module-loading boundary on purpose.
+async function snapshotFacts(harnessConfig: string): Promise<Array<{ label: string; value: string }>> {
+  fs.writeFileSync(path.join(agentHome, "config.yaml"), harnessConfig);
+  const { RuntimeState } = await import("../src/dashboard/state");
+  const { loadConfig } = await import("../src/config");
+  const snapshot = new RuntimeState(loadConfig("examples/config.yaml")).getSnapshot(0);
+  const entry = snapshot.knowledgeBase.entries.find((item) => item.id === "system_environment");
+  expect(entry).toBeDefined();
+  return entry?.facts ?? [];
+}
+
+describe("dashboard runtime context with an unreadable harness config", () => {
+  it.each([
+    ["a document with no content", "# nothing configured yet\n"],
+    ["unparseable YAML", "model:\n\tdefault: gpt\n"],
+    ["a truncated flow collection", "model: [\n"],
+  ])("degrades one panel when the harness config is %s", async (_label, contents) => {
+    const facts = await snapshotFacts(contents);
+
+    // The file is present and was read; only the parse of it failed.
+    expect(facts.find((fact) => fact.label === "Config file")?.value).toBe("configured");
+    expect(facts.find((fact) => fact.label === "Config keys")?.value).toBe("none");
+    expect(facts.find((fact) => fact.label === "Model")?.value).toBe("unknown");
+  });
+
+  it("still reports keys when the harness config parses", async () => {
+    const facts = await snapshotFacts("model:\n  default: gpt-5\ndisplay:\n  skin: dark\n");
+
+    expect(facts.find((fact) => fact.label === "Config keys")?.value).toBe("model, display");
+    expect(facts.find((fact) => fact.label === "Model")?.value).toBe("gpt-5");
+    expect(facts.find((fact) => fact.label === "Display skin")?.value).toBe("dark");
+  });
+});