feat(settings): admin switch to allow or block members' test runs

Settings → AI tools → Tests on this server (admin, S3 only). Stored in
/opt/agenthub/app/member-policy.json, which member-guard.js reads as the
member at each Bash call — no restart; no file = blocked. GET/PUT
/api/ai-tools/member-policy, audited, 409 ENOS3 outside S3.

server/__tests__/member-guard.test.js

@@ -77,6 +77,18 @@ describe("member-guard: a test run or a container command", () => {
     assert.equal(o.permissionDecision, "deny");
     assert.match(o.permissionDecisionReason, /own machine/);
   });
+
+  it("lets everything through once an admin allows tests", () => {
+    const out = [];
+    const write = process.stdout.write;
+    process.stdout.write = (s) => out.push(String(s));
+    try {
+      guardTool({ tool_name: "Bash", tool_input: { command: "npx vitest run" } }, true);
+    } finally {
+      process.stdout.write = write;
+    }
+    assert.equal(out.length, 0);
+  });
 });
 
 /** A fake /proc: one dir per pid with stat, cmdline; owner is this process (uid). */
@@ -93,6 +105,28 @@ function fakeProc(list) {
   return root;
 }
 
+describe("member-policy: the admin's switch, read by the guard", () => {
+  it("blocks tests without a file, and writes a world-readable one", () => {
+    const dir = fs.mkdtempSync(path.join(os.tmpdir(), "ah-app-"));
+    const prev = process.env.AGENTHUB_APP_ROOT;
+    process.env.AGENTHUB_APP_ROOT = dir;
+    try {
+      const policy = require("../lib/member-policy.js");
+      assert.equal(policy.read().allowTests, false);
+      fs.writeFileSync(path.join(dir, policy.FILE), "not json");
+      assert.equal(policy.read().allowTests, false);
+      assert.equal(policy.setAllowTests(true).allowTests, true);
+      const f = path.join(dir, policy.FILE);
+      assert.equal(fs.statSync(f).mode & 0o777, 0o644);
+      assert.equal(policy.read(f).allowTests, true);
+      assert.equal(policy.setAllowTests(false).allowTests, false);
+    } finally {
+      if (prev === undefined) delete process.env.AGENTHUB_APP_ROOT;
+      else process.env.AGENTHUB_APP_ROOT = prev;
+    }
+  });
+});
+
 describe("ai-procs: a member's top-level AI sessions", () => {
   const uid = process.getuid();
   const root = fakeProc([